How to Write SEO-Friendly Alt Text for Images (With Examples)

If you've spent any time learning about SEO, you've probably come across the term "alt text."

Many website owners know they should add alt text to images, but they're often unsure what to write. Some add only a few words. Others stuff keywords into every image. Many skip alt text entirely.

The truth is that alt text serves an important purpose for both accessibility and image SEO.

When written correctly, it helps search engines understand images and improves the experience for people who use screen readers. Google specifically recommends using descriptive alt text to help understand image content while also supporting accessibility.

In this guide, you'll learn exactly how to write SEO-friendly alt text, see real examples, and discover common mistakes to avoid.

What Is Alt Text?

Alt text (alternative text) is a short description added to an image.

It is stored within the image's HTML code and is used when:

• An image fails to load

• A visitor uses a screen reader

• Search engines analyze image content

Alt text acts as a textual replacement for visual content. It helps people who cannot see the image understand what information the image provides.

Example

<img src="golden-retriever-puppy.webp" alt="Golden retriever puppy playing with a red ball in the grass">

This description gives both users and search engines valuable context about the image.

Why Alt Text Matters for SEO

Search engines have become much better at understanding images, but they still rely on text signals.

Google uses information such as page content, image filenames, surrounding text, and alt text to understand image subject matter.

Good alt text can help:

• Improve image understanding

• Support image search visibility

• Improve accessibility

• Provide context when images cannot load

However, alt text should not be treated as a keyword-stuffing opportunity.

Why Alt Text Matters for Accessibility

Accessibility is actually the primary purpose of alt text.

Screen readers read alt text aloud to users who cannot see images. This allows visitors with visual impairments to understand information that would otherwise be unavailable.

A well-written alt description creates a better experience for all users.

The Golden Rule of Alt Text

The simplest rule is:

Describe the image as if you were explaining it to someone who cannot see it.

Focus on the purpose and meaning of the image rather than trying to force keywords into every description.

Google recommends writing useful, information-rich alt text that is relevant to the page context.

Example 1: Blog Photography

Bad

dog

Worse

dog puppy dog puppy pet dog training puppy dog

Better

Golden retriever puppy running through a grassy park

The better example describes what the image actually shows.

Example 2: Website Performance Article

Imagine your article discusses image optimization.

Bad

computer

Better

Website speed report showing image optimization improvements

The better version provides context related to the article topic.

Example 3: Product Image

Bad

shoe

Better

Women's white leather running shoe with blue accents

Specific descriptions help both accessibility and image understanding.

Example 4: Infographics

Infographics require a slightly different approach.

Bad

marketing infographic

Better

Infographic showing five steps for improving website image optimization

For complex graphics, summarize the purpose of the image and explain detailed information within the article itself.

Avoid Keyword Stuffing

One of the biggest image SEO mistakes is keyword stuffing.

Bad Example

image SEO image optimization image SEO guide image SEO checklist image SEO tips

This provides a poor experience and offers little value.

Google specifically advises against filling alt attributes with keywords.

Instead:

Better

Checklist showing image SEO best practices for websites

Natural descriptions work better.

Don't Start With "Image of"

Many beginners write:

Image of a mountain

or

Picture of a mountain

Most screen readers already identify content as an image.

A better version is:

Snow-covered mountain peak at sunrise

Concise descriptions improve usability.

Keep Alt Text Concise

Good alt text is usually short.

You do not need to describe every tiny detail.

Too Long

A smiling woman wearing a blue sweater sitting at a wooden table while drinking coffee near a large window overlooking a city skyline during sunrise.

Better

Woman drinking coffee while working at a desk

Focus on what matters in context.

Decorative Images Don't Need Descriptions

Not every image needs detailed alt text.

For purely decorative images:

alt=""

An empty alt attribute tells screen readers to ignore the image. This is recommended for decorative elements that add no informational value.

Examples include:

• Decorative dividers

• Background patterns

• Visual flourishes

• Design accents

Match Alt Text to Page Context

Context matters.

Consider the same image of a bird.

In a wildlife article:

Black-capped chickadee perched on a snowy branch

In an article about bird migration:

Black-capped chickadee commonly found in mixed-species flocks

The description changes based on the content surrounding the image.

Alt Text and File Names Work Together

While alt text is important, descriptive file names also help search engines understand images.

Bad filename:

IMG_4587.jpg

Better filename:

website-speed-report.jpg

Google recommends descriptive filenames rather than generic image names.

Alt Text Checklist

Before publishing, ask:

✓ Does the alt text describe the image?

✓ Is it useful for someone using a screen reader?

✓ Is it concise?

✓ Does it avoid keyword stuffing?

✓ Does it fit the page context?

✓ Is it natural to read?

If the answer is yes, you're probably on the right track.

Common Alt Text Mistakes

Missing Alt Text

Many images are uploaded without any description.

Keyword Stuffing

Repeating keywords excessively harms usability.

Generic Descriptions

Words such as:

• image

• photo

• graphic

usually provide little value.

Overly Long Descriptions

Keep descriptions focused and relevant.

Ignoring Context

Alt text should support the content around the image.

Final Thoughts

Writing SEO-friendly alt text is not complicated.

The best alt text focuses on helping people first and search engines second.

Describe images clearly, keep descriptions concise, avoid keyword stuffing, and match the description to the page context.

When combined with image compression, proper filenames, modern formats, and good website performance practices, alt text becomes an important part of a complete image SEO strategy.

A few extra seconds spent writing meaningful alt text can improve accessibility, strengthen image SEO, and create a better experience for every visitor.