Why Alt Text Matters More Than You Think

Alt text (short for alternative text) is a short written description added to an image’s HTML code. It serves two critical purposes: it makes your website accessible to people using screen readers, and it helps search engines understand what your images depict.

If you have ever wondered how to write alt text for images that actually performs well in search results while keeping your site inclusive, this guide is for you. We will walk through clear rules, real examples for different image types, and the most common mistakes that hurt both your rankings and your users.

What Is Alt Text and Where Does It Go?

In HTML, alt text is added inside the image element like this:

<img src="blue-running-shoes.jpg" alt="Blue Nike running shoes on a white background">

In WordPress and most CMS platforms, you simply fill in the “Alternative Text” field when you upload or edit an image. No coding required.

Screen readers read this text aloud to visually impaired users. When an image fails to load, browsers display the alt text instead. And Google’s crawlers rely on it to index and rank your images in search results.

The Core Rules: How to Write Alt Text for Images

Follow these principles every time you write alt text, regardless of the image type.

1. Be Specific and Succinct

Aim for one to two short sentences, or roughly 125 to 150 characters. Describe the main message the image communicates rather than listing every tiny detail.

2. Focus on Key Elements

Ask yourself: Why did I choose this image? That reason is what belongs in the alt text. If the image shows a team meeting, mention the setting and activity, not the color of the chairs.

3. Include Text That Appears in the Image

If your image contains words, such as a chart label, a quote overlay, or a button, always include that text in your alt text. A screen reader cannot read text embedded in an image file.

4. Use One or Two Relevant Keywords

Naturally weave in a keyword that matches the page topic. This helps with image SEO. But do not stuff multiple keywords into one alt attribute.

5. Never Start with “Image of” or “Picture of”

Screen readers already announce that the element is an image. Starting with “Image of” is redundant and wastes valuable character space.

6. Do Not Use the File Name

Alt text like IMG_4892.jpg or screenshot-final-v2 provides zero value to users or search engines.

Do’s and Don’ts at a Glance

Do	Don’t
Describe the purpose of the image	Write vague text like “photo” or “image1”
Keep it under 150 characters	Write a full paragraph
Use natural language with a keyword	Stuff multiple keywords unnaturally
Leave alt empty for decorative images	Describe decorative dividers or background patterns
Include on-image text in the alt attribute	Ignore text overlays, chart labels, or captions in images
Write unique alt text for each image	Copy-paste the same alt text across multiple images

Alt Text Examples by Image Type

Different images serve different purposes. Here is how to handle the most common types you will encounter on a website.

Product Photos

Product images need to be descriptive enough to help someone make a purchase decision without seeing the photo.

Bad Alt Text	Good Alt Text
shoes	Women's white leather sneakers with platform sole by BrandX
product-photo-final.jpg	Stainless steel insulated water bottle, 750ml, in matte black

Tip: Include the product name, color, material, and size when relevant. Think about what a shopper would want to know.

Infographics and Charts

Infographics pack a lot of information into one image. Your alt text should summarize the main takeaway, not describe every data point.

Bad Alt Text	Good Alt Text
infographic	Bar chart showing a 40% increase in mobile traffic from 2023 to 2025
chart data	Pie chart comparing email marketing ROI across five industries, with retail leading at 38%

Tip: If the infographic is complex, provide a longer description in the body text or use a longdesc attribute or an accessible summary below the image.

Decorative Images

Decorative images add visual appeal but carry no informational value. Think of background textures, divider lines, or purely aesthetic flourishes.

For these, use an empty alt attribute:

<img src="wave-divider.svg" alt="">

This tells screen readers to skip the image entirely, which creates a smoother experience for users who rely on assistive technology.

Team and People Photos

Bad Alt Text	Good Alt Text
team	Five team members collaborating around a whiteboard in a modern office
photo of person	Sarah Chen, Head of Marketing, speaking at the 2026 company summit

Tip: When the person’s identity matters to the context, include their name and role. When it does not, describe the activity and setting instead.

Screenshots

Screenshots appear frequently in tutorials and how-to articles. Focus on what the screenshot is demonstrating.

• Bad: screenshot
• Good: WordPress media library showing the alt text field highlighted in the image attachment details panel

Logos

If a logo links to a homepage, the alt text should identify the brand, not describe the graphic design.

• Bad: logo with blue circle and white letters
• Good: JAB Digital homepage

Images Used as Links or Buttons

When an image is the only content inside a link or button, the alt text must describe the link’s destination or action, not the image itself. This is all a screen reader has to work with.

• Bad: red arrow
• Good: Go to pricing page

Common Alt Text Mistakes That Hurt SEO and Accessibility

Even experienced content creators fall into these traps. Here are the mistakes we see most often during site audits.

1. Keyword stuffing. Writing alt text like best running shoes buy running shoes cheap running shoes online will trigger search engine penalties and annoy screen reader users.
2. Leaving alt text blank on meaningful images. Empty alt attributes are correct for decorative images, but leaving them blank on informational images creates accessibility gaps and missed SEO opportunities.
3. Using the same alt text for every image on the page. Each image is unique. Treat the alt text the same way you would treat any other on-page content: make it original.
4. Writing overly long descriptions. Screen readers will read the entire string without pause. If your alt text sounds like a novel, it becomes a barrier instead of a help.
5. Describing what the image looks like instead of what it means. A photo of a handshake on a business page is not about “two hands clasping.” It is about “partnership” or “client agreement.”
6. Ignoring context. The same stock photo of a laptop could need completely different alt text depending on whether it appears on a tech review page or a remote work blog post. Always write alt text relative to the surrounding content.

A Simple Process to Follow Every Time

Use this quick checklist before you publish any image:

1. Determine the image type. Is it informational, functional (link/button), or decorative?
2. If decorative, set alt="" and move on.
3. If functional, describe the action or destination.
4. If informational, write a concise description that captures the image’s purpose in context.
5. Include any visible text that appears in the image.
6. Add one relevant keyword naturally if it fits.
7. Check the length. Aim for under 150 characters.
8. Read it aloud. Does it make sense without seeing the image? If yes, you are done.

Can AI Tools Write Alt Text for You?

Yes, tools like ChatGPT and various alt text generators can produce descriptions for images. They are useful as a starting point, especially when you have hundreds of images to process. However, AI-generated alt text often lacks context. It describes what an image looks like rather than what it means on your specific page.

Our recommendation: use AI to draft, then always review and edit manually. Adjust the description so it fits the page’s topic, includes relevant keywords naturally, and matches the intent behind why you placed the image there.

Alt Text and Image SEO: The Bigger Picture

Writing strong alt text is one piece of a larger image SEO strategy. To get the most out of your visual content, also consider:

• Descriptive file names. Rename IMG_3021.jpg to blue-ceramic-coffee-mug.jpg before uploading.
• Proper image compression. Fast-loading images rank better. Use WebP or AVIF formats where possible.
• Responsive images. Serve appropriately sized images for different screen sizes using srcset.
• Structured data. For product images, recipe images, or how-to images, add relevant schema markup.
• Captions and surrounding text. Google also uses nearby text to understand an image. Place images close to the content they relate to.

Frequently Asked Questions

What is alt text for an image?

Alt text is a short text description assigned to an image in HTML using the alt attribute. It tells screen readers and search engines what the image shows. When an image cannot load, the browser displays this text instead.

What is a good alt text for images?

Good alt text is concise (under 150 characters), describes the image’s purpose in context, includes relevant keywords naturally, and avoids starting with “image of” or “picture of.” It should make sense to someone who cannot see the image.

Can ChatGPT write alt text for images?

ChatGPT and other AI tools can generate alt text, but the results often lack page-specific context. Use AI as a drafting tool and always review the output manually to ensure accuracy, relevance, and proper keyword usage.

What should I write for decorative images?

Decorative images that carry no informational value should have an empty alt attribute: alt="". This tells assistive technology to skip the image, which improves the experience for screen reader users.

How long should alt text be?

Keep alt text to approximately 125 to 150 characters. Some screen readers cut off text after 125 characters, so front-load the most important information. For complex images like infographics, provide additional context in the surrounding body text.

Does alt text help SEO?

Yes. Alt text is one of the primary signals Google uses to understand image content. Well-written alt text can help your images appear in Google Image Search and contribute to the overall relevance of your page for target keywords.