How to Write Alt Text for Images: SEO Best Practices with Examples

Alt Text for SEO: The Practical Guide With Real Examples

If you’ve ever wondered why some images rank in Google Images while others sit invisible at the bottom of search results, the answer often comes down to one small but mighty HTML attribute: alt text. Writing effective alt text for SEO is part technical skill, part copywriting craft, and entirely essential if you care about both accessibility and organic visibility.

In this guide, we’ll walk through exactly how to write alt text that pleases screen readers, search engines, and your human visitors. You’ll get good vs. bad examples across multiple industries, a checklist you can apply immediately, and the most common mistakes that quietly tank your image SEO.

What Is Alt Text (and Why Should You Care in 2026)?

Alt text (alternative text) is a short written description added to an image’s HTML. It serves three main purposes:

• Accessibility: Screen readers read alt text aloud to visually impaired users.
• SEO: Search engines use it to understand image content and context.
• Fallback: If an image fails to load, the alt text appears in its place.

Here’s what it looks like in code:

<img src="red-running-shoes.jpg" alt="Red Nike running shoes on a forest trail">

Google has confirmed multiple times that alt text helps it understand image subject matter. With visual search now driving a significant share of e-commerce discovery in 2026, ignoring alt text means leaving real traffic on the table.

The Anatomy of Great Alt Text for SEO

Good alt text follows a simple formula:

[Subject] + [Action or context] + [Relevant detail or keyword, if natural]

Keep these principles in mind:

1. Be specific, not generic. “Dog” is weak. “Golden retriever puppy chewing a tennis ball” is strong.
2. Stay under 125 characters. Most screen readers cut off after that point.
3. Include keywords naturally. Never stuff. If the keyword doesn’t fit, leave it out.
4. Don’t start with “Image of” or “Picture of.” Screen readers already announce that it’s an image.
5. Skip decorative images. Use alt="" for purely decorative graphics so screen readers can ignore them.
6. Match the surrounding content. Context matters. The same photo may need different alt text on different pages.

Good vs. Bad Alt Text Examples by Industry

Theory only goes so far. Here are concrete, side-by-side examples to model your own writing on.

E-commerce

Travel & Hospitality

SaaS & Tech

Food & Restaurants

Healthcare

7 Common Alt Text Mistakes That Hurt Your SEO

1. Keyword stuffing. Writing “best running shoes cheap running shoes buy running shoes” looks spammy and can trigger Google penalties.
2. Leaving alt text empty on meaningful images. An empty alt on a product photo wastes a ranking signal.
3. Using the filename as alt text. alt="IMG_4823.jpg" tells search engines nothing.
4. Repeating the same alt text on every image. Each image deserves a unique description.
5. Describing emotions instead of content. “A happy moment” doesn’t help search engines understand what’s in the image.
6. Ignoring infographics. Summarize the key data point or conclusion in plain language.
7. Forgetting linked images. If an image is also a link, the alt text should describe the link destination.

Special Cases: When Alt Text Rules Bend

Decorative Images

Background patterns, dividers, and purely aesthetic graphics should use alt="" (empty alt). This signals to screen readers to skip the image entirely.

Logos

Use the company name plus “logo” if it adds context: alt="Internet Wonders eZine logo".

Charts and Infographics

Summarize the takeaway, not every data point. Example: “Bar chart showing organic traffic grew 47% from January to June 2026.” Then provide the full data table elsewhere on the page.

Images of Text

Transcribe the text exactly. If a banner image says “Summer Sale 30% Off,” the alt text should match.

Quick Alt Text Checklist Before Publishing

• Is the description specific and accurate?
• Is it under 125 characters?
• Does it avoid “image of” or “picture of”?
• Is the target keyword included only if natural?
• Is every meaningful image covered, and every decorative image set to alt=""?
• Does it make sense when read aloud?

How Alt Text Fits Into a Bigger Image SEO Strategy

Alt text alone won’t rocket your images to the top of Google. Pair it with:

• Descriptive file names (e.g., red-running-shoes.jpg instead of IMG_4823.jpg)
• Compressed image sizes using WebP or AVIF formats
• Responsive images with srcset for mobile
• Structured data for product, recipe, or article images
• Surrounding text context that reinforces the image topic

FAQ: Alt Text for SEO

What is good alt text for SEO?

Good alt text is a concise, specific description of an image (ideally under 125 characters) that naturally includes a relevant keyword when appropriate and accurately reflects what the image shows.

Does adding alt text improve SEO?

Yes. Alt text helps Google understand image content, improves your chances of ranking in Google Images, supports accessibility (a confirmed ranking factor through Core Web Vitals and UX signals), and provides additional on-page context.

How long should alt text be?

Aim for under 125 characters. Most screen readers truncate beyond this length, and Google generally favors concise, descriptive text.

Should every image have alt text?

Every meaningful image should. Decorative images should have an empty alt attribute (alt="") so screen readers skip them.

Can I use AI to generate alt text?

AI tools can speed up the process, but always review the output. Automatic descriptions often miss brand-specific or contextual details that matter for SEO and accessibility.

What’s the difference between alt text and title text?

Alt text describes the image for accessibility and SEO. Title text appears as a tooltip when users hover over an image and is largely optional for SEO purposes.

Final Thoughts

Writing strong alt text for SEO isn’t about gaming Google. It’s about making your content accessible to every user and giving search engines the context they need to surface your images. Treat each alt attribute as a tiny piece of copywriting: clear, specific, useful. Do this consistently across your site, and you’ll see compounding gains in both image search traffic and overall user experience.

Start with your highest-traffic pages today, audit the alt text, and apply the framework above. Your visitors, screen readers, and rankings will thank you.