Image Alt Text for SEO: Accessibility and Search Visibility

What Is Alt Text?

Alt text (short for alternative text) is a written description of an image that you add to your website's HTML. It looks like this:

<img src="red-leather-wallet.jpg" alt="Red leather bifold wallet open showing card slots">

The alt text serves as a text substitute for the image. If the image fails to load, the alt text appears in its place. Screen readers used by visually impaired people read the alt text aloud. And search engines use it to understand what an image shows, since they can't see images the way humans can.

Why Alt Text Matters for SEO

Search engines are very good at reading text. They're much less capable when it comes to understanding what's in an image — especially nuanced subject matter, text inside images, or visual context. Alt text fills that gap.

When you add descriptive alt text to your images, you give Google the information it needs to:

• Understand the subject of the image and how it relates to the surrounding content
• Index your images and show them in Google Image Search
• Reinforce what your page is about by seeing consistent, relevant image descriptions

Google Image Search drives real traffic. If you sell products, have a portfolio, or run a visual business like photography, interior design, or food, image search can be a meaningful traffic source — but only if your images are properly described.

Why Alt Text Matters for Accessibility

According to the World Health Organization, over 2 billion people worldwide have some form of vision impairment. Many of them use screen readers — software that reads web page content aloud — to navigate the internet.

When a screen reader encounters an image with no alt text, it either says nothing or reads out the filename (which is often something unhelpful like "IMG_4892.jpg"). When alt text is present and descriptive, the person knows exactly what the image shows.

Beyond being good practice, accessibility is increasingly becoming a legal requirement in many countries. Web accessibility guidelines (WCAG) require meaningful alt text for informational images.

How to Write Good Alt Text

Be Descriptive and Specific

Describe what's actually in the image as concisely as possible. Think about what you'd say if you were describing the image to someone over the phone.

Include Keywords Naturally

If a relevant keyword fits naturally in the description, include it. For example, if your page is about "handmade leather wallets," it makes sense for your product images to have alt text that includes "handmade leather wallet."

However, don't stuff keywords into alt text that don't belong there. "Red wallet leather wallet buy leather wallet online" looks like spam and can hurt rather than help.

Keep It Reasonably Concise

Alt text doesn't need to be a novel. Aim for a clear description in 5–15 words. If the image is complex — like an infographic — you might need a longer description or a separate text caption on the page.

Don't Start With "Image of" or "Photo of"

Screen readers already announce that it's an image before reading the alt text. Starting with "image of" just wastes words and adds redundancy.

When to Leave Alt Text Empty

Not every image needs a text description. Decorative images — backgrounds, dividers, purely decorative icons — should have empty alt text (alt=""). This tells screen readers to skip the image entirely, which improves the listening experience for visually impaired users.

The key question is: does this image convey information? If removing it would make the page harder to understand, it needs alt text. If it's purely decorative, use an empty alt attribute.

Alt Text for Common Image Types

Product Images

Include the product name, key attributes (color, material, type), and any other details that would help someone understand what they're looking at. "Blue ceramic coffee mug with white stripe pattern, 12oz" is much better than "mug."

People and Portraits

For photos of people, describe what's happening and include the person's name if relevant. "Sarah Chen, founder of Bloom Bakery, holding a sourdough loaf" gives context that a blind user can understand.

Charts and Graphs

For data visualizations, summarize the key finding. "Bar chart showing 43% increase in website traffic from January to March 2024." If the chart is complex, consider adding a data table below it.

Logos

Just use the company or brand name. "Harlow Goods logo" is perfectly fine.

How to Add Alt Text in Common Platforms

You don't need to write HTML to add alt text. Every major platform has built-in alt text fields:

• WordPress: When you add an image, click on it and look for the "Alt Text" field in the right sidebar.
• Shopify: In your product media, click the "Edit alt text" option that appears when you hover over an image.
• Squarespace: Click an image block and select "Edit" to find the alt text field.
• Wix: Right-click an image and choose "Edit Alt Text."