Alt text is the short description of an image that lives in the HTML but doesn’t display on the page. It’s read aloud by screen readers for visually impaired users, and it’s how search engines understand what an image shows.
Every image on your site that isn’t purely decorative should have alt text. The purely decorative exception is real — a subtle background texture or a decorative divider doesn’t need a description, and adding one just adds noise. But every photograph, product image, illustration, or diagram does.
What makes good alt text?
Describe what the image actually shows, in plain words. Not “image of a dog” — just “dog.” Not “beautiful sunset photo” — just “sunset over the Pacific from Long Beach.” Short, factual, specific.
Don’t stuff keywords. Screen reader users notice immediately, and it reads as spammy to Google, too.
The decorative exception
Some images really are just visual decoration — icons paired with a text heading, background textures, dividers between sections. For those, you still need an alt attribute, but you can leave it empty (alt=””). This explicitly tells screen readers “this image is decorative, please skip it” — which is different from having no alt attribute at all, which tells screen readers nothing and makes them guess.
What about stock photos?
Stock photos are the trickiest case. They’re usually added to pages as atmospheric filler — a laptop, a smiling person, a coffee cup. Technically they’re content, not decoration, so they need alt text. But describing every coffee mug feels silly.
The pragmatic rule: describe what’s in the photo, briefly and factually. “Laptop on a wooden desk” is fine. “Smiling woman at a workspace” is fine. Keep it under 125 characters or so. Nobody’s going to judge you for not being poetic about a stock photo.
How to fix it
If you have a hundred images and no alt text on any of them, you don’t have to fix it all at once. Start with the ones on your homepage and your top five most-visited pages. That covers most of the real impact — search engines weight page authority, so alt text on your homepage matters more than alt text on page 12 of your blog archive.
Most content management systems have a dedicated alt text field when you upload or edit an image. Use it. It takes seconds per image and the cumulative SEO and accessibility benefit is real.
