Lesson 04: HTML Attributes: Syntax, Key Attributes, Quoting Rules & Best Practices

Phase 1 of 16

Lesson Introduction

Welcome to Lesson 4! Over the last three lessons you have built a solid foundation:

Lesson 2 · You wrote your first real HTML pages using core tags
Lesson 3 · You understood exactly what an HTML element is and how nesting works

Now it is time to fully master HTML attributes · the extra instructions you write inside opening tags to give elements more power, behaviour, and meaning.

You have already used attributes. Every time you wrote href="..." in a link or src="..." in an image, you used an attribute. But in this lesson you will truly understand them · what they are, why they exist, all their rules, and how to use each major one with confidence.

By the end of this lesson you will be able to:

Define what an HTML attribute is and explain its syntax precisely
Write attributes correctly using the name="value" format
Explain and use the seven most important HTML attributes: href, src, width, height, alt, style, lang, and title
Understand the difference between absolute and relative URLs in the src attribute
Know the quoting rules for attribute values and when each applies
Follow professional best practices (lowercase, always quote)
Diagnose and fix all common attribute mistakes

Real-world connection: Attributes are the knobs and dials of HTML. The tag says what the element is · the attributes control how it behaves. A link without href goes nowhere. An image without src shows nothing. A page without lang confuses search engines and accessibility tools. Mastering attributes means mastering control.

✏️ Your Task

- Diagnose and fix all common attribute mistakes > Real-world connection: Attributes are the knobs and dials of HTML. The tag says *what* the element is · the attributes control *how* it behaves. A link without href goes nowhere. An image without src shows nothing. A page without lang confuses search engines and accessibility tools. Mastering attributes means mastering control. ·

Phase 2 of 16

Prerequisite Concepts

Quick Recap · What Is an Element? What Is a Tag?

From Lesson 3:

A tag is just the label: <a> or </a>
An element is the full package: <a href="...">text</a>
Attributes live inside the opening tag · never in the closing tag

You have already seen attributes used. This lesson explains every rule governing them.

✏️ Your Task

Practise what you just learned about Prerequisite Concepts. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 3 of 16

Part 1 · What Is an HTML Attribute?

The Definition

An HTML attribute is extra information added to an HTML element's opening tag that modifies or extends the element's behaviour, appearance, or meaning.

Think of a tag as a basic instruction and its attributes as the settings for that instruction.

Analogy: Imagine ordering a coffee. The coffee type (latte, espresso) is like the tag · it names the thing. The customisations (size: large, milk: oat, sugar: none) are like attributes · they specify exactly how you want that thing to be. Without the customisations, you just get a default coffee. With them, you get exactly what you need.

The Syntax · Name/Value Pairs

Every attribute follows this exact structure:

code

name="value"

Where:

name · the name of the attribute (what setting you are configuring)
= · separates the name from the value
"value" · the value of that setting, always wrapped in quotes

Attributes are placed inside the opening tag, after the tag name, separated by a space:

html

<tagname name="value">Content</tagname>

Here is a real example:

html

<a href="https://www.w3schools.com">Visit W3Schools</a>

Breaking it down:

code

<a   href="https://www.w3schools.com"   >Visit W3Schools</a>
 │        │                      │      │
 │        attribute name         │      │
 │                               │      │
 tag name                    value      closing bracket of opening tag

Part	What it is
`a`	The tag name (anchor / link)
`href`	The attribute name
`=`	The separator between name and value
`"https://www.w3schools.com"`	The attribute value (in double quotes)
`Visit W3Schools`	The element's content (the clickable text)
`</a>`	The closing tag

Multiple Attributes on One Element

An element can have more than one attribute. Simply separate them with spaces inside the opening tag:

html

<img src="photo.jpg" alt="A smiling student" width="300" height="200">

This <img> element has four attributes:

src="photo.jpg" · the image file to display
alt="A smiling student" · the text description
width="300" · 300 pixels wide
height="200" · 200 pixels tall

Order does not matter. You can write attributes in any order within the opening tag and they will work identically. However, consistency and readability matter · develop a habit of writing attributes in a logical order (e.g., src before alt before sizing attributes).

Four Universal Rules for Attributes

Before learning individual attributes, memorise these four rules:

Attributes always go in the opening tag · never in the closing tag
Attributes are written as name/value pairs · name="value"
Attribute values must always be quoted · use "double" or 'single' quotes
Attribute names should always be lowercase · href not HREF

We will look at the quoting and case rules in detail in Part 7.

✏️ Your Task

Practise what you just learned about What Is an HTML Attribute?. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 4 of 16

Part 2 · The `href` Attribute

What Is `href`?

The href attribute belongs to the <a> (anchor) tag. It stands for Hypertext REFerence and holds the URL (web address) of the destination the link navigates to when clicked.

html

<a href="https://www.w3schools.com">Visit W3Schools</a>

Without href, the <a> tag renders as styled text but does nothing when clicked. href is what makes a link actually go somewhere.

Simple Example · A Basic Link

html

<!DOCTYPE html>
<html>
<body>

<h1>My Favourite Resources</h1>
<a href="https://www.w3schools.com">Visit W3Schools</a>

</body>
</html>

Expected output in browser:

code

My Favourite Resources

Visit W3Schools    ← blue, underlined, navigates to w3schools.com when clicked

Second Example · Links in Context

html

<!DOCTYPE html>
<html>
<body>

<h1>Learning Resources</h1>
<p>Start with <a href="https://www.w3schools.com">W3Schools</a> for tutorials.</p>
<p>Practice projects at <a href="https://www.github.com">GitHub</a>.</p>
<p>Ask questions at <a href="https://stackoverflow.com">Stack Overflow</a>.</p>

</body>
</html>

Expected output in browser:

code

Learning Resources

Start with W3Schools for tutorials.
Practice projects at GitHub.
Ask questions at Stack Overflow.

(W3Schools, GitHub, and Stack Overflow each appear as clickable blue links within their sentences.)

Thinking prompt: What happens if you write href="" (an empty value)? The browser treats it as a link to the current page · clicking it just reloads the same page.

Common Beginner Mistakes with `href`

html

<!-- WRONG 1: Missing https:// — browser looks for a local file -->
<a href="www.google.com">Google</a>

<!-- WRONG 2: href in the closing tag — attributes only go in opening tags -->
<a>Visit Google</a href="https://www.google.com">

<!-- WRONG 3: Space between attribute name and = sign -->
<a href ="https://www.google.com">Google</a>

<!-- CORRECT: href in opening tag, no spaces around =, full URL -->
<a href="https://www.google.com">Google</a>

✏️ Your Task

Ask questions at Stack Overflow.

` Expected output in browser: ` Learning Resources Start with W3Schools for tutorials.

Phase 5 of 16

Part 3 · The `src` Attribute

What Is `src`?

The src attribute belongs to the <img> tag. It stands for source and holds the path (file location or URL) of the image to display.

html

<img src="img_girl.jpg">

Without src, the browser has no idea which image to show. The result is a broken image icon.

Absolute URLs vs Relative URLs

There are two ways to specify the path in src (and also in href). Understanding this is critical for all web development.

Absolute URL

An absolute URL is a complete, full web address · it includes the protocol (https://), the domain name, and the full path to the file.

html

<img src="https://www.w3schools.com/images/img_girl.jpg" alt="Girl with a jacket">

Absolute URLs point to files on other websites (external). They always begin with https:// or http://.

Important warnings about external images:

The image may be under copyright · you need permission to use it
You have no control over external images · the owner can delete or change the image at any time, breaking your page
Loading external images can be slower than loading local ones

Relative URL

A relative URL points to a file on your own website. It does not include the domain name · it is described relative to the current file's location.

Type 1 · Same folder as the HTML file:

html

<img src="img_girl.jpg" alt="Girl with a jacket">

If your HTML file is at mysite.com/index.html and the image is also in the root folder, the browser looks for mysite.com/img_girl.jpg.

Type 2 · File is in a subfolder:

html

<img src="images/img_girl.jpg" alt="Girl with a jacket">

The browser looks one level deeper into an images folder.

Type 3 · URL starts with a slash (relative to domain root):

html

<img src="/images/img_girl.jpg" alt="Girl with a jacket">

The / at the start means "start from the root of the domain". Regardless of which folder the HTML file is in, the browser looks for images/img_girl.jpg at the root of the website.

Best practice tip: Almost always use relative URLs for images and files on your own website. If you ever move your site to a different domain name, relative URLs keep working · absolute URLs to your old domain would break.

Simple Example · Relative URL Image

Imagine your project folder looks like this:

code

my-website/
├── index.html
├── photo.jpg
└── images/
    └── logo.png

html

<!DOCTYPE html>
<html>
<body>

<!-- Image in the same folder -->
<img src="photo.jpg" alt="My profile photo" width="200" height="200">

<!-- Image in the images subfolder -->
<img src="images/logo.png" alt="My website logo" width="150" height="50">

</body>
</html>

Expected output: Both images display, because the browser finds them by following the relative paths from the HTML file's location.

Second Example · Absolute URL Image (from the web)

html

<!DOCTYPE html>
<html>
<body>

<h1>Planet Earth</h1>
<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/97/The_Earth_seen_from_Apollo_17.jpg/320px-The_Earth_seen_from_Apollo_17.jpg"
     alt="Earth seen from space"
     width="320"
     height="320">
<p>This image is hosted on Wikipedia's servers.</p>

</body>
</html>

Expected output:

code

Planet Earth

[Photo of Earth from space — 320×320 pixels]

This image is hosted on Wikipedia's servers.

Thinking prompt: What would happen to this page if Wikipedia deleted or renamed that image file? The image would show a broken icon, and your page would look incomplete. This is why hosting your own images and using relative URLs is safer.

✏️ Your Task

Practise what you just learned about The src Attribute. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 6 of 16

Part 4 · The `width` and `height` Attributes

What Are They?

The width and height attributes on <img> tags set the dimensions of an image in pixels (px).

html

<img src="img_girl.jpg" width="500" height="600">

This displays the image at 500 pixels wide and 600 pixels tall.

Why Should You Always Include Them?

Beyond just controlling image size, specifying width and height serves a crucial technical purpose: it reserves space on the page before the image loads.

When a browser loads a page, it first reads the HTML and builds the page layout. If image dimensions are not specified, the browser does not know how much space to leave for the image. When the image eventually loads, the entire page layout suddenly shifts · text jumps, buttons move, users lose their place. This jarring experience is called layout shift and is considered a major web performance problem.

By specifying width and height, the browser pre-allocates the correct space, so nothing jumps when the image loads.

Simple Example · Image with Fixed Dimensions

html

<!DOCTYPE html>
<html>
<body>

<h2>With width and height specified:</h2>
<img src="cat.jpg" alt="A tabby cat" width="300" height="200">

<h2>Same image, no dimensions — risk of layout shift:</h2>
<img src="cat.jpg" alt="A tabby cat">

</body>
</html>

Expected output for first image: Displays at exactly 300×200 pixels.

Expected output for second image: Displays at whatever the image's natural size is (could be enormous or tiny).

Thinking prompt: If you set width="600" but keep height="200" on an image that is naturally square (e.g., 400×400), what would happen? The image would appear stretched horizontally and squashed vertically. To avoid distortion when resizing, set only width · the browser will automatically scale height proportionally. Or set only height and let width scale.

Example · Resizing Without Distortion

html

<!-- Set only width — height scales automatically, no distortion -->
<img src="profile.jpg" alt="My profile photo" width="250">

<!-- Set only height — width scales automatically, no distortion -->
<img src="banner.jpg" alt="Website banner" height="80">

✏️ Your Task

Practise what you just learned about The width and height Attributes. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 7 of 16

Part 5 · The `alt` Attribute

What Is `alt`?

The alt attribute on <img> provides alternative text · a written description of the image. It is displayed when:

The image file cannot be found (broken link, wrong filename)
The internet connection is too slow to load the image
The user is using a screen reader (assistive software for visually impaired users)

html

<img src="img_girl.jpg" alt="Girl with a jacket">

The alt attribute is described as required · while it is technically optional in the code, omitting it is considered a serious accessibility and quality failure.

Why Is `alt` Text One of the Most Important Attributes in HTML?

Reason 1 · Accessibility. Over 250 million people worldwide have significant visual impairments. Screen reader software reads web pages aloud to them. When the screen reader reaches an image, it reads the alt text. Without alt, the user hears nothing · the image is completely invisible to them.

Reason 2 · Broken images. When an image fails to load (wrong filename, slow connection, offline), the browser displays the alt text in the image's place. A good alt text ensures the user still understands what was supposed to be there.

Reason 3 · Search engine optimisation (SEO). Search engines like Google are essentially blind to images · they cannot "see" them. They read the alt text to understand what an image depicts. Good alt text helps your pages rank better for relevant searches.

Reason 4 · Professional standards. Web accessibility is required by law in many countries (e.g., Section 508 in the USA, the Equality Act in the UK, and equivalent laws in Nigeria and across Africa). Missing alt text can make your website legally non-compliant.

How to Write Good `alt` Text

A good alt attribute:

Describes what is in the image specifically and concisely
Does not start with "Image of..." or "Picture of..." · screen readers already announce it is an image
Is meaningful to someone who cannot see the image

html

<!-- POOR alt text — too vague -->
<img src="product.jpg" alt="image">
<img src="team.jpg" alt="photo">

<!-- GOOD alt text — specific and meaningful -->
<img src="product.jpg" alt="Nike Air Max 270 running shoe in black and white">
<img src="team.jpg" alt="Our five-person development team at the Lagos Tech Hub">

For decorative images (images that are purely visual decoration with no informational value), use an empty alt="":

html

<!-- Empty alt tells screen readers to skip this decorative image entirely -->
<img src="divider-line.png" alt="">

Simple Example · Demonstrating alt in Action

html

<!DOCTYPE html>
<html>
<body>

<h1>Correct image (alt shown only if image fails):</h1>
<img src="img_girl.jpg" alt="Girl with a jacket" width="500" height="600">

<h1>Wrong filename (alt text displayed instead):</h1>
<img src="wrong_filename.jpg" alt="Girl with a jacket" width="500" height="600">

</body>
</html>

Expected output · first image: The photo displays normally (alt text is invisible unless you inspect with a screen reader).

Expected output · second image: A broken image icon and the text Girl with a jacket appears in its place · because the file wrong_filename.jpg does not exist.

Second Example · Real-World Alt Text in a News Article

html

<!DOCTYPE html>
<html>
<body>

<h1>Lagos Tech Week 2025</h1>

<img src="keynote.jpg"
     alt="Tech entrepreneur speaking on stage at Lagos Tech Week 2025, with a large screen showing a rocket launch behind them"
     width="800"
     height="450">

<p>Over 3,000 developers attended this year's Lagos Tech Week.</p>

</body>
</html>

This alt text is excellent because it:

Describes the scene specifically
Gives context (the event name)
Describes what is visible on the background screen
Would be genuinely useful to a visually impaired person

✏️ Your Task

Practise what you just learned about The alt Attribute. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 8 of 16

Part 6 · The `style` Attribute

What Is `style`?

The style attribute is used to add inline CSS styling directly to an individual HTML element. It controls visual properties like text colour, font size, background colour, margins, and much more.

html

<p style="color:red;">This is a red paragraph.</p>

Expected output:

code

This is a red paragraph.    ← displayed in red text

How the `style` Attribute Works

The value of the style attribute is written as one or more CSS property:value pairs, separated by semicolons (;):

code

style="property:value;"
style="property1:value1; property2:value2;"

For example:

html

<p style="color:blue; font-size:20px; background-color:yellow;">
  Styled paragraph
</p>

Expected output: Blue text, 20px font size, on a yellow background.

Simple Example · Styling Different Elements

html

<!DOCTYPE html>
<html>
<body>

<h1 style="color:navy;">My Web Page</h1>
<p style="color:green;">This paragraph is green.</p>
<p style="color:red; font-size:18px;">This paragraph is red and larger.</p>
<p style="background-color:lightblue;">This paragraph has a blue background.</p>

</body>
</html>

Expected output in browser:

code

My Web Page          ← heading in navy blue
This paragraph is green.   ← green text
This paragraph is red and larger.   ← red text, bigger font
This paragraph has a blue background.  ← text on light blue background

Second Example · Styling a Heading and an Image

html

<!DOCTYPE html>
<html>
<body>

<h1 style="color:purple; text-align:center;">Welcome to My Website</h1>

<img src="photo.jpg"
     alt="My profile photo"
     width="200"
     height="200"
     style="border:3px solid black;">

<p style="font-family:Arial; color:grey;">
  This text uses a sans-serif font in grey.
</p>

</body>
</html>

Expected output: Purple centred heading, image with a black border, grey Arial paragraph text.

A Note on Inline Styles vs External CSS

While style attributes work perfectly and are great for learning, professional developers use external CSS files for styling rather than inline style attributes on every element.

The reason: imagine you have 100 paragraphs and you want them all green. With style attributes, you must add style="color:green;" to all 100. With an external CSS file, you write one rule that applies to all paragraphs at once.

You will learn CSS in full in a separate course. For now, style attributes are the perfect way to see styling take effect immediately and understand how CSS properties work.

✏️ Your Task

Practise what you just learned about The style Attribute. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 9 of 16

Part 7 · The `lang` Attribute

What Is `lang`?

The lang attribute is placed on the <html> element and declares the natural language of the web page's content.

html

<html lang="en">

This tells search engines, browsers, and accessibility tools: "The content of this page is written in English."

Why Is `lang` Important?

For search engines: Google and other search engines use lang to serve your page to users searching in the right language.

For browsers: Some browsers use lang to decide whether to offer a translation option.

For screen readers: Screen readers use lang to apply the correct language pronunciation rules. If lang is missing or wrong, a screen reader might try to read English text with French pronunciation rules · making it completely incomprehensible for the listener.

For accessibility compliance: Including lang is a requirement of the WCAG (Web Content Accessibility Guidelines), which many countries' accessibility laws are based on.

Language Codes

Language codes follow an international standard called BCP 47. The most common format is:

Two-letter language code alone: "en" (English), "fr" (French), "ar" (Arabic), "yo" (Yoruba), "ha" (Hausa)
Language code + country code: "en-US" (English, United States), "en-GB" (English, United Kingdom), "en-NG" (English, Nigeria), "pt-BR" (Portuguese, Brazil)

The country code helps when the same language has regional variations (e.g., American English vs British English spellings).

Simple Example · Setting Language to English (UK)

html

<!DOCTYPE html>
<html lang="en-GB">
<body>

<h1>Welcome to My Website</h1>
<p>This page is written in British English.</p>

</body>
</html>

Expected output: Page looks identical to any other page · but browsers, screen readers, and search engines now know the language is British English.

Second Example · A Multilingual Note

html

<!DOCTYPE html>
<html lang="en-NG">
<body>

<h1>My Nigerian Tech Blog</h1>
<p>This page is in English as used in Nigeria.</p>

<!-- A section in Yoruba would ideally use a span with lang attribute -->
<p><span lang="yo">E kaaro</span> — that means "Good morning" in Yoruba.</p>

</body>
</html>

New concept shown above: The lang attribute is not just for <html> · it can also be placed on any individual element to declare a different language for that specific piece of content. This helps screen readers switch pronunciation correctly mid-sentence.

Language Code Quick Reference

Language	Code	With Region
English	`en`	`en-US`, `en-GB`, `en-NG`
French	`fr`	`fr-FR`, `fr-CA`
Spanish	`es`	`es-ES`, `es-MX`
Arabic	`ar`	`ar-EG`, `ar-SA`
Portuguese	`pt`	`pt-BR`, `pt-PT`
Yoruba	`yo`	·
Hausa	`ha`	·
Igbo	`ig`	·
Swahili	`sw`	·

✏️ Your Task

Practise what you just learned about The lang Attribute. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 10 of 16

Part 8 · The `title` Attribute

What Is `title`?

The title attribute adds extra descriptive information about an element. When a user hovers their mouse cursor over the element, the browser displays this text as a small pop-up tooltip.

html

<p title="I'm a tooltip">This is a paragraph.</p>

Expected output: The paragraph text displays normally. When you hover the mouse over it, a small grey tooltip box appears showing I'm a tooltip.

Why Use `title`?

The title attribute is used to provide supplementary context that does not need to be visible on the page at all times, but is helpful when the user wants more information.

Common uses:

Explaining what an abbreviated term means
Providing extra detail about a link's destination
Adding a description to an image that already has alt text

Simple Example · Tooltip on a Link

html

<!DOCTYPE html>
<html>
<body>

<a href="https://www.w3schools.com"
   title="Go to W3Schools — the world's largest web development learning site">
  Visit W3Schools
</a>

</body>
</html>

Expected output: "Visit W3Schools" appears as a clickable link. Hovering the mouse over it shows the tooltip text.

Second Example · Tooltip on an Abbreviation

html

<!DOCTYPE html>
<html>
<body>

<p>
  The <abbr title="World Wide Web Consortium">W3C</abbr> maintains the
  standards for HTML, CSS, and many other web technologies.
</p>

<p title="Last updated: April 2026">
  This article was recently updated.
</p>

</body>
</html>

Expected output: Normal paragraph text. Hovering over W3C shows World Wide Web Consortium. Hovering over the second paragraph shows Last updated: April 2026.

Note: The <abbr> tag (abbreviation element) is specifically designed to work with title for expanding abbreviations. You will learn more about semantic HTML elements in a later lesson.

`title` vs `alt` · Know the Difference

These two attributes are frequently confused by beginners:

Attribute	Element	Purpose	When shown
`alt`	`<img>` only	Describes the image · required for accessibility	When image fails to load; read by screen readers
`title`	Any element	Provides supplementary information · optional	On mouse hover as a tooltip

html

<!-- This is correct: alt for accessibility, title for tooltip info -->
<img src="chart.png"
     alt="Bar chart showing Q3 revenue by region"
     title="Data source: 2025 Annual Report, page 14"
     width="600"
     height="400">

The alt here helps visually impaired users understand the chart. The title provides a source citation that sighted users can see on hover.

✏️ Your Task

Practise what you just learned about The title Attribute. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 11 of 16

Part 9 · Always Use Lowercase Attribute Names

The Rule

Just as with HTML tag names (Lesson 3), attribute names should always be written in lowercase.

The HTML5 standard does not technically require it · HREF, Href, and href all work identically in a browser. But professional standards and the W3C recommendation require lowercase, and for the same reasons as with tags:

Readability: All-lowercase code is much easier to scan
Compatibility: Some stricter document types (XHTML) require lowercase
Consistency: When mixed with CSS and JavaScript (which are case-sensitive), lowercase-everywhere prevents hard-to-spot bugs

html

<!-- WRONG: uppercase attribute names -->
<a HREF="https://www.google.com">Google</a>
<img SRC="photo.jpg" ALT="My photo" WIDTH="200" HEIGHT="200">

<!-- WRONG: mixed case -->
<a Href="https://www.google.com">Google</a>

<!-- CORRECT: all lowercase -->
<a href="https://www.google.com">Google</a>
<img src="photo.jpg" alt="My photo" width="200" height="200">

Expected output: Identical for all three · the browser does not care. But your code quality is far superior with the lowercase version.

✏️ Your Task

Practise what you just learned about Always Use Lowercase Attribute Names. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 12 of 16

Part 10 · Always Quote Attribute Values

The Rule

Attribute values should always be wrapped in quotes. The HTML5 standard technically allows some attribute values without quotes, but W3C strongly recommends always quoting, and demands quotes for XHTML.

html

<!-- "Bad" (technically works in some cases, but discouraged) -->
<a href=https://www.w3schools.com>Visit W3Schools</a>

<!-- "Good" (always correct) -->
<a href="https://www.w3schools.com">Visit W3Schools</a>

Expected output: Both display identically as a clickable link in most cases. But quoting is always safer.

Why Quoting Is Mandatory · Not Just Recommended

There is one case where missing quotes always breaks the code: when the attribute value contains a space.

html

<!-- BROKEN: The title value has a space — browser only reads "Description" -->
<p title=Description of W3Schools>

<!-- CORRECT: Quotes allow the full phrase including spaces -->
<p title="Description of W3Schools">

Without quotes, the browser reads title=Description and then treats of and W3Schools as separate broken attributes · completely wrong. This is not a maybe-it-works situation: it always fails without quotes.

This is the core reason the rule exists: quoting handles all values safely, including those with spaces, so you never have to think about whether this particular value needs quotes.

Double Quotes vs Single Quotes

HTML supports both "double" and 'single' quotes for attribute values. They are completely equivalent in the browser's eyes.

html

<!-- Both of these are valid and produce identical results -->
<a href="https://www.google.com">Google</a>
<a href='https://www.google.com'>Google</a>

When to use single quotes: When the attribute value itself contains double quotes, you must use single quotes as the outer wrapper to avoid confusion:

html

<!-- WRONG: double quotes inside double quotes breaks the attribute -->
<p title="John "ShotGun" Nelson">

<!-- CORRECT: use single quotes when value contains double quotes -->
<p title='John "ShotGun" Nelson'>

The reverse also applies: If your value contains single quotes, use double quotes as the outer wrapper:

html

<!-- CORRECT: double quotes when value contains single quotes/apostrophe -->
<p title="Nigeria's largest city is Lagos">

Best practice: Default to double quotes for all attribute values (it is the overwhelming convention in HTML). Only switch to single quotes when the value itself contains double quotes.

Summary Table · Quoting Rules

Situation	Use	Example
Normal value (no special characters)	`"double"`	`href="https://google.com"`
Value contains double quotes	`'single'`	`title='He said "Hello"'`
Value contains single quote/apostrophe	`"double"`	`title="Nigeria's capital"`
Value contains spaces	Either · but must use one	`alt="A blue car"`
Value contains no spaces or special chars	`"double"` (preferred)	`width="300"`

✏️ Your Task

Practise what you just learned about Always Quote Attribute Values. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 13 of 16

Part 11 · All Key Attributes Quick Reference

Here is a consolidated reference table for every attribute covered in this lesson:

Attribute	Which Tag(s)	What It Does	Example
`href`	`<a>`	URL the link navigates to	`href="https://google.com"`
`src`	`<img>`	Path or URL of image to display	`src="photo.jpg"`
`width`	`<img>`	Image width in pixels	`width="300"`
`height`	`<img>`	Image height in pixels	`height="200"`
`alt`	`<img>`	Text description of image	`alt="A smiling student"`
`style`	Any element	Inline CSS styling	`style="color:red;"`
`lang`	`<html>`	Language of the page	`lang="en-NG"`
`title`	Any element	Tooltip text on hover	`title="More info here"`

✏️ Your Task

Practise what you just learned about All Key Attributes Quick Reference. Open your editor, type the examples above by hand, modify them, and observe what changes.

Phase 14 of 16

Guided Practice Exercises

🎯 Your Challenge

Work through these in order. Each one builds confidence with a specific attribute concept.

Exercise 1 · Label Every Attribute

For each HTML line below, identify the element name, all attribute names, and all attribute values.

Line 1:

✏️ Task

Practise what you just learned about Guided Practice Exercises. Open your editor, type the examples above by hand, modify them, and observe what changes.

html

<a href="https://www.bbc.com" title="Visit BBC News website">BBC News</a>

Answers:

Element: <a> (anchor/link)
Attribute 1 name: href | value: "https://www.bbc.com"
Attribute 2 name: title | value: "Visit BBC News website"
Content: BBC News

Line 2:

html

<img src="team.jpg" alt="Our five-person team at the office" width="600" height="400">

Answers:

Element: <img> (image, empty element)
Attribute 1 name: src | value: "team.jpg"
Attribute 2 name: alt | value: "Our five-person team at the office"
Attribute 3 name: width | value: "600"
Attribute 4 name: height | value: "400"
Content: none (empty element)

Line 3:

html

<p style="color:purple; font-size:16px;" title="Introduction paragraph">
  Welcome to my website.
</p>

Answers:

Element: <p> (paragraph)
Attribute 1 name: style | value: "color:purple; font-size:16px;"
Attribute 2 name: title | value: "Introduction paragraph"
Content: Welcome to my website.

Exercise 2 · Fix Five Attribute Errors

The following code contains five separate attribute mistakes. Find them all and write the corrected version.

Broken code:

html

<!DOCTYPE html>
<HTML lang=en>
<body>

<h1 STYLE="color:blue">My Technology Blog</h1>
<p>Read the latest at <a HREF=https://www.techcrunch.com title='TechCrunch'>TechCrunch</a>.</p>
<img src="laptop.jpg" ALT=A laptop on a desk width="400" height=300>

</body>
</html>

Five errors:

<HTML> · tag name not lowercase (covered in Lesson 3)
lang=en · attribute value not quoted
STYLE= · attribute name not lowercase
HREF= · attribute name not lowercase, and value not quoted
ALT=A laptop on a desk · attribute name not lowercase AND value with spaces is not quoted, AND height=300 is not quoted

Corrected code:

html

<!DOCTYPE html>
<html lang="en">                                    <!-- Fix 1: lowercase tag; Fix 2: lang value quoted -->
<body>

<h1 style="color:blue;">My Technology Blog</h1>    <!-- Fix 3: lowercase style -->
<p>Read the latest at <a href="https://www.techcrunch.com" title="TechCrunch">TechCrunch</a>.</p>
                                                    <!-- Fix 4: lowercase href, value quoted -->
<img src="laptop.jpg"
     alt="A laptop on a desk"                       <!-- Fix 5: lowercase alt, value with spaces quoted -->
     width="400"
     height="300">                                  <!-- height value quoted -->

</body>
</html>

Expected output in browser:

code

My Technology Blog    ← blue heading

Read the latest at TechCrunch.    ← "TechCrunch" is a clickable link

[Laptop image, 400×300 pixels]

Exercise 3 · Absolute vs Relative URLs

You are building a website with this folder structure:

code

my-portfolio/
├── index.html
├── about.html
├── images/
│   ├── profile.jpg
│   └── project1.jpg
└── projects/
    └── project-details.html

Write the correct src or href attribute value for each scenario:

Scenario 1: You are in index.html and want to display images/profile.jpg.

html

<img src="images/profile.jpg" alt="My profile photo">

Scenario 2: You are in project-details.html (inside the projects/ folder) and want to display images/project1.jpg (which is up one level in the parent folder).

html

<img src="../images/project1.jpg" alt="Project 1 screenshot">

.. means "go up one folder level" · it is a standard file path convention.

Scenario 3: You are in index.html and want to link to about.html (same folder).

html

<a href="about.html">About Me</a>

Scenario 4: You are in index.html and want to link to project-details.html (inside the projects/ subfolder).

html

<a href="projects/project-details.html">View Project Details</a>

Scenario 5: You want to display an image from an external URL.

html

<img src="https://example.com/images/banner.jpg" alt="External banner image">

Exercise 4 · Build a Correctly Attributed Image Gallery

Objective: Create a simple photo gallery page that uses all the image-related attributes correctly.

Requirements:

Valid document structure with lang attribute on <html>
A page <h1> title with a style attribute (any colour)
Three <img> elements, each with src, alt, width, and height
A brief <p> caption under each image, using title attribute for extra info
All attributes in lowercase with values quoted

Solution:

html

<!DOCTYPE html>
<html lang="en-NG">
<body>

<h1 style="color:darkgreen;">My Photography Gallery</h1>

<h2>Nature Photos</h2>

<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Biome-wet-tropical.jpg/320px-Biome-wet-tropical.jpg"
     alt="Lush tropical rainforest with tall green trees"
     width="320"
     height="213">
<p title="Taken at Okomu National Park, Nigeria">
  Tropical rainforest canopy — one of Earth's most biodiverse ecosystems.
</p>

<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/24701-nature-natural-beauty.jpg/320px-24701-nature-natural-beauty.jpg"
     alt="Calm river flowing through green hills at sunrise"
     width="320"
     height="213">
<p title="Sunrise photography requires patience and early mornings">
  A tranquil river at sunrise — stillness captured in a frame.
</p>

<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/African_savanna_at_Ngorongoro.jpg/320px-African_savanna_at_Ngorongoro.jpg"
     alt="Wide open African savanna landscape with acacia trees"
     width="320"
     height="213">
<p title="The African savanna spans across multiple countries">
  African savanna — vast, open, and breathtaking.
</p>

</body>
</html>

Expected output: Three images displayed with their captions. Hovering over each caption reveals its tooltip. Page heading is in dark green.

Phase 15 of 16

HTML Attributes Code Challenges

These challenges test everything from this lesson: attribute syntax, specific attributes, quoting rules, URL types, and best practices.

Challenge 1 · Spot the Wrong Attributes

Study this element closely. There are three attribute mistakes. Name and fix all three.

html

<img SRC=banner.png ALT="Promotional banner for our summer sale 2025" Width="800" height="200">

Mistakes:

SRC · should be lowercase src
SRC=banner.png · the value banner.png has no quotes
Width · should be lowercase width

Corrected version:

html

<img src="banner.png" alt="Promotional banner for our summer sale 2025" width="800" height="200">

Challenge 2 · Write a Complete, Correct `<html>` Opening Tag

Task: Write the opening <html> tag for a web page written in Nigerian English.

Solution:

html

<html lang="en-NG">

Bonus · for a French-Canadian page:

html

<html lang="fr-CA">

Challenge 3 · Inline Style Practice

Task: Write a single <p> element that has ALL of the following style properties applied using the style attribute:

Text colour: navy
Background colour: lightyellow
Font size: 18px
Font family: Georgia

Solution:

html

<p style="color:navy; background-color:lightyellow; font-size:18px; font-family:Georgia;">
  This paragraph demonstrates multiple inline CSS properties applied via the style attribute.
</p>

Expected output: Navy text, on a light yellow background, in Georgia font at 18px size.

Challenge 4 · Quoting Edge Cases

Task: Write each of the following as a valid HTML attribute value, choosing the correct quote type:

A title value that reads: John "The Eagle" Okafor
A title value that reads: Nigeria's capital city is Abuja
An alt value that reads: Chart showing Africa's GDP growth from 2020 to 2025
A title value that reads: He said: "It's a beautiful day in Lagos!"

Solutions:

html

<!-- 1: Contains double quotes — use single quote wrapper -->
<p title='John "The Eagle" Okafor'>Player Profile</p>

<!-- 2: Contains apostrophe/single quote — use double quote wrapper -->
<p title="Nigeria's capital city is Abuja">Geography</p>

<!-- 3: Contains apostrophe — use double quote wrapper -->
<img src="chart.png" alt="Chart showing Africa's GDP growth from 2020 to 2025">

<!-- 4: Contains BOTH types — use single quotes outside (or escape characters, covered later) -->
<p title='He said: "It&apos;s a beautiful day in Lagos!"'>Quote</p>

The ' in example 4 is an HTML entity · a special code for the apostrophe character. You will learn HTML entities in a later lesson. For now, the best approach when a value has both types of quotes is to use ' for the apostrophe.

Challenge 5 · Build a Complete, Correct Attributes Showcase Page

Task: Build a single HTML page that demonstrates every attribute from this lesson at least once. The page should be a "Tech Tools" resource page.

Requirements: lang, href, src, alt, width, height, style, title

Solution:

html

<!DOCTYPE html>
<html lang="en">
<body>

<h1 style="color:darkblue; text-align:center;">Essential Developer Tools</h1>

<p style="font-size:16px;" title="Last reviewed: April 2026">
  Below are some of the most useful tools for web developers at all levels.
</p>

<h2>Documentation &amp; Learning</h2>

<img src="https://www.w3schools.com/images/w3schools_logo_436_2.png"
     alt="W3Schools logo — free web development tutorials"
     width="150"
     height="48"
     style="border:1px solid #cccccc;">

<p>
  <a href="https://www.w3schools.com" title="Visit W3Schools for free HTML, CSS, and JavaScript tutorials">
    W3Schools
  </a>
  — the world's largest web development learning platform.
</p>

<h2>Code &amp; Version Control</h2>

<img src="https://github.githubassets.com/images/modules/logos_page/GitHub-Mark.png"
     alt="GitHub logo — a circle with a cat silhouette inside"
     width="80"
     height="80">

<p>
  <a href="https://www.github.com" title="GitHub: host your code and collaborate with developers worldwide">
    GitHub
  </a>
  — store, share, and collaborate on code projects.
</p>

<h2>Community &amp; Support</h2>

<p>
  <a href="https://stackoverflow.com"
     title="Stack Overflow: ask programming questions and get answers from experts">
    Stack Overflow
  </a>
  — the largest Q&amp;A community for developers.
</p>

</body>
</html>

The & you see above is the HTML entity for the & character. Because & has a special meaning in HTML, you must write it as & to display it literally. You will learn this fully in the HTML Entities lesson.

Expected output:

code

         Essential Developer Tools        ← centred, dark blue

Below are some of the most useful tools...    ← normal text with tooltip on hover

Documentation & Learning

[W3Schools logo]

W3Schools — the world's largest web development learning platform.

Code & Version Control

[GitHub logo]

GitHub — store, share, and collaborate on code projects.

Community & Support

Stack Overflow — the largest Q&A community for developers.

✏️ Your Task

Task: Write the opening tag for a web page written in Nigerian English. Solution: `html ` Bonus · for a French-Canadian page: `html ` ·

Phase 16 of 16

Common Beginner Mistakes · Full Summary for This Lesson

Syntax Mistakes:

Putting attributes in the closing tag: </a href="#"> · never do this
Forgetting the = between name and value: <img src"photo.jpg"> · always include =
Using spaces around =: <a href = "url"> · no spaces around the equals sign
Writing attribute names in uppercase: SRC, ALT, HREF · always lowercase

Quoting Mistakes:

No quotes on values with spaces: alt=A blue car · always quote
Using no quotes at all: href=https://google.com · always quote
Starting with double but ending with single: alt="My photo' · must use the same quote type
Using double quotes inside double-quoted values: title="John "Big" Smith" · use single quotes outside

href Mistakes:

Missing https://: href="www.google.com" · browser looks for a local file named www.google.com
Putting the URL as content instead of as a value: <a>https://google.com</a> · no href means no navigation

src Mistakes:

Wrong relative path: src="photo.jpg" when the image is actually in src="images/photo.jpg"
Using an absolute URL for your own site's images: causes domain-change breakage
Linking to external images without permission (copyright violation)

alt Mistakes:

Missing alt entirely · always include it
Vague alt text: alt="image" · be specific and descriptive
Starting with "Image of": alt="Image of a cat" · screen readers already announce it is an image

lang Mistakes:

Forgetting lang entirely on <html> · always include it
Using the wrong code: lang="english" instead of lang="en" · codes are standardised
Putting lang on <body> instead of <html> · it belongs on <html>

style Mistakes:

Missing the colon between property and value: style="colorred" · should be style="color:red;"
Missing the semicolons between multiple properties: style="color:red font-size:16px" · needs ; between them

✏️ Your Task

Practise what you just learned about Common Beginner Mistakes · Full Summary for This Lesson. Open your editor, type the examples above by hand, modify them, and observe what changes.

🏗️ Build It — Mini Project

Project Overview

Combine every concept from Lessons 2, 3, and 4 into one polished, complete, professionally structured team profile page.

Project Overview

Project name: Our Team Goal: A multi-section team profile page using all key attributes from this lesson alongside correct document structure and element nesting from previous lessons.

Stage 1 · Skeleton with Language

starter.html

<!DOCTYPE html>
<html lang="en-NG">
<body>

<!-- Content coming in next stages -->

</body>
</html>

Lesson 04 complete! 🎉

You covered:

✅ Lesson Introduction
✅ Prerequisite Concepts
✅ Part 1 · What Is an HTML Attribute?
✅ Part 2 · The `href` Attribute
✅ Part 3 · The `src` Attribute
✅ Part 4 · The `width` and `height` Attributes
✅ Part 5 · The `alt` Attribute
✅ Part 6 · The `style` Attribute

← Lesson 03 Lesson 05 →

HTML Attributes: Syntax, Key Attributes, Quoting Rules & Best Practices

👋 Welcome to Lesson 04

Quick Recap · What Is an Element? What Is a Tag?

The Definition

The Syntax · Name/Value Pairs

Multiple Attributes on One Element

Four Universal Rules for Attributes

What Is href?

Simple Example · A Basic Link

Second Example · Links in Context

Common Beginner Mistakes with href

What Is src?

Absolute URLs vs Relative URLs

Absolute URL

Relative URL

Simple Example · Relative URL Image

Second Example · Absolute URL Image (from the web)

What Are They?

Why Should You Always Include Them?

Simple Example · Image with Fixed Dimensions

Example · Resizing Without Distortion

What Is alt?

Why Is alt Text One of the Most Important Attributes in HTML?

How to Write Good alt Text

Simple Example · Demonstrating alt in Action

Second Example · Real-World Alt Text in a News Article

What Is style?

How the style Attribute Works

Simple Example · Styling Different Elements

Second Example · Styling a Heading and an Image

A Note on Inline Styles vs External CSS

What Is lang?

Why Is lang Important?

Language Codes

Simple Example · Setting Language to English (UK)

Second Example · A Multilingual Note

Language Code Quick Reference

What Is title?

Why Use title?

Simple Example · Tooltip on a Link

Second Example · Tooltip on an Abbreviation

title vs alt · Know the Difference

The Rule

The Rule

Why Quoting Is Mandatory · Not Just Recommended

Double Quotes vs Single Quotes

Summary Table · Quoting Rules

Exercise 1 · Label Every Attribute

Exercise 2 · Fix Five Attribute Errors

Exercise 3 · Absolute vs Relative URLs

Exercise 4 · Build a Correctly Attributed Image Gallery

Challenge 1 · Spot the Wrong Attributes

Challenge 2 · Write a Complete, Correct <html> Opening Tag

Challenge 3 · Inline Style Practice

Challenge 4 · Quoting Edge Cases

Challenge 5 · Build a Complete, Correct Attributes Showcase Page

Project Overview

Stage 1 · Skeleton with Language

Lesson 04 complete! 🎉

What Is `href`?

Common Beginner Mistakes with `href`

What Is `src`?

What Is `alt`?

Why Is `alt` Text One of the Most Important Attributes in HTML?

How to Write Good `alt` Text

What Is `style`?

How the `style` Attribute Works

What Is `lang`?

Why Is `lang` Important?

What Is `title`?

Why Use `title`?

`title` vs `alt` · Know the Difference

Challenge 2 · Write a Complete, Correct `<html>` Opening Tag