Alt Text Done Right: Why Most Websites Still Get This Basic Rule Wrong

ClearPath Team · 2026-07-26 · 7 min read

Alt text has been part of web standards since the 1990s. It's one of the first things anyone learns in an accessibility training. And yet, year after year, it keeps showing up near the top of every list of the most common accessibility failures on the web. That's not a knowledge problem anymore. It's an execution problem.

The latest WebAIM Million report, which scans the home pages of the top one million websites, found that 16.2% of all home page images (10.8 per page on average) had missing alternative text, not counting images intentionally marked as decorative. The good news is that number is moving in the right direction. While there were notably more images, the proportion of images missing alt text dropped from 18.5% in 2025. The bad news is the web is getting more visual, not less. Home pages are becoming increasingly graphical with the number of home page images nearly doubling in 8 years, and there were over 66.6 million images in the sample, a 13.6% increase in only one year. More images means more chances to get it wrong.

And missing alt text isn't even the whole story. Plenty of images that do have alt text still fail their users, because the text itself is useless. A file name, the word "image," or a description that just repeats the caption sitting right next to it doesn't help anyone using a screen reader. It just adds noise.

Why this one attribute matters so much

Alt text exists because images are, by default, invisible to a screen reader. Without a text alternative, a blind or low vision user either hears nothing where the image sits, or worse, hears the screen reader announce a cryptic file name instead. Neither gives them the information a sighted visitor gets automatically.

This isn't a niche concern. Alt text is also the underlying requirement behind WCAG's very first success criterion, 1.1.1 Non-text Content, which requires that all non-text content presented to the user has a text alternative that serves the equivalent purpose, the foundational requirement for images conveying the same information as the visual content unless purely decorative. It's a Level A criterion, the most basic tier of conformance, which tells you how fundamental this is considered.

The three questions that decide what to write

Most alt text mistakes come from skipping a simple decision process. Before typing anything into that field, ask what kind of image you're actually dealing with.

Is it purely decorative?

If an image adds visual flourish but carries no information, a background swirl, a stock photo of people shaking hands next to a paragraph that already explains the point, it should get an empty alt attribute: alt="". This isn't laziness. It's the correct technique. As accessibility guidance puts it, a null text alternative should be provided when the only purpose of an image is to add visual decoration to the page, rather than to convey information important to understanding the page. Leaving the attribute off entirely is actually worse than an empty one, because assistive tech can't reliably tell the difference between "forgotten" and "intentionally decorative."

Is it informative?

Photos, charts, illustrations, screenshots, anything that adds meaning needs a real description. The standard guidance here is straightforward: for informative images that graphically represent concepts and information, the text alternative should be at least a short description conveying the essential information presented by the image. Think about what a sighted user takes away from the image in two seconds, then write that.

Is it functional?

Icons that act as buttons or links are their own category. A magnifying glass icon that submits a search form doesn't need "magnifying glass" as alt text. It needs "Search," because that's what it does. Describe the action, not the artwork.

Practical rules that actually hold up

• Keep it tight. Aim for roughly 100 to 140 characters. Long enough to convey the point, short enough that a screen reader user isn't stuck listening to a paragraph before they can move on.
• Skip the throat-clearing. Don't start with "image of" or "picture of." Screen readers already announce that it's an image, so those words just waste the listener's time.
• Never leave it as a file name. Plenty of CMS platforms default to the uploaded file name if you don't fill in the field. "IMG_4021.jpg" tells a screen reader user nothing.
• Match alt text to purpose, not appearance. Describe what the image is doing on the page, not just what's in the frame.
• For product images on ecommerce sites, be specific. Color, pattern, material, distinguishing features. A shopper who can't see the photo is relying entirely on your words to decide whether that sweater is the one they want.
• Watch for redundant or repetitive text. If the same generic phrase gets pasted across dozens of images, or if the alt text just repeats a caption sitting right below it, screen reader users end up hearing everything twice.

Don't skip the manual check

Automated scanners can tell you whether an alt attribute exists. They can't tell you whether it's any good. Tools that check for missing alt attributes are catching the easy half of the problem. A human still needs to read through image descriptions occasionally and ask whether they'd actually make sense read aloud, out of context, to someone who can't see the page. That's the part scanners miss, and it's often where the real user experience gap lives.

The bottom line

Alt text is one of the simplest, cheapest fixes in web accessibility, and it's still one of the most commonly ignored. Fixing it doesn't require a redesign or a developer sprint. It requires someone going through the images on your site, asking what each one is for, and writing a few honest words that describe it. Given how basic the requirement is, and how much it affects real people trying to use your site, there's not much excuse left for getting it wrong.