HTML Image alt Attribute – A Complete Beginner’s Guide

Introduction: Why the `alt` Attribute Is Important

When you add an image to a webpage, not every user can see that image.

Situations where images may not be visible:

Slow internet connection
Image file missing or broken
Screen reader users (visually impaired)
Text-only browsers
Search engines crawling your page

To handle this, HTML provides the alt attribute.

👉 The alt attribute is mandatory for professional, accessible, and SEO-friendly websites.

What Is the HTML Image alt Attribute?

he alt attribute (alternative text) provides a text description of an image.

In simple words:

The alt text explains what the image is about when the image cannot be seen.

Basic Syntax of `alt` Attribute

<img src="image.jpg" alt="Description of the image">

Key Points

alt stands for alternative text
It is written inside the <img> tag
It does not appear visually unless the image fails to load

Example 1: Image with `alt` Text

<img src="mountain.jpg" alt="Snow-covered mountain under blue sky">

What Happens

Image loads → user sees the image
Image fails → alt text is displayed
Screen reader → reads the alt text aloud

What Happens If alt Is Missing?

Bad Example:

Problems:

Screen readers announce “image” only
Accessibility guidelines are violated
SEO value is lost
HTML validation errors

Always include alt.

Why the alt Attribute Is Important

Accessibility (Most Important)

Screen readers rely on alt text
Helps visually impaired users understand images
Required by WCAG accessibility guidelines

SEO (Search Engine Optimization)

Search engines cannot “see” images
alt text helps Google understand image content
Improves image search rankings

Fallback Text

Displays text if image fails to load
Useful on slow networks

Good vs Bad alt Text Examples

Example	Bad Usage ❌	Good Usage ✅
Logo	`<img src="logo.png" alt="image">`	`<img src="logo.png" alt="BigDrop Academy Logo">`
Product	`<img src="car.jpg" alt="">`	`<img src="car.jpg" alt="Red sports car with black roof">`
Decorative	`<img src="line.png" alt="line">`	`<img src="line.png" alt="">` (empty alt for purely decorative images)

How to Write Good alt Text (Best Practices)

Describe what’s important in the image
Keep it short (5–15 words)
Be specific
Write naturally (like a sentence fragment)
Consider the context

Decorative Images and Empty alt Attribute

Some images are purely decorative and do not add meaning.

Example: Decorative Image

alt="" tells screen readers to ignore the image.

⚠️ Use this only when the image adds no informational value.

alt Attribute vs title Attribute

Attribute	Purpose
`alt`	Accessibility & SEO
`title`	Tooltip on hover

Example

title is optional, alt is essential.

Using alt Text for Images as Links

When an image is clickable, the alt text acts as the link text.

Important for screen readers
Improves usability

Common Beginner Mistakes

Leaving out alt
Using file names as alt text
Keyword stuffing for SEO
Writing “image of” or “picture of”
Using same alt text for multiple images

SEO Tips for alt Attribute

Use relevant keywords naturally
Do not stuff keywords
Match image content with page content
Use unique alt text for each image

Keyword Stuffing

Natural

Real-World Example

<h1>Our Services</h1>

<img src="web-design.png" alt="Web designer creating website layout on computer">

<p>We offer professional web design services.</p>

FAQs: HTML Image alt Attribute

What is the alt attribute used for?

To provide alternative text for images.

Is alt attribute mandatory?

Yes, for accessibility and good HTML practice.

Can alt text be empty?

Yes, but only for decorative images.

Does alt text help SEO?

Yes, especially for image search.

Should alt text include keywords?

Yes, but naturally and relevantly.