Good alt text describes what the image is for, not what it looks like. That one sentence resolves most of the confusion, and most of the bad alt text on the web comes from ignoring it.
Missing and useless alt text is reliably the largest category of finding on a WordPress site nobody has checked. It is also the part no tool can do for you, because the right words depend on why the image is on the page.
The rule, stated properly
Ask yourself: if this image vanished, what would the reader lose?
Write that.
A photograph of a team on an About page is not “group of people smiling”. Its purpose is to show who you are, so the useful alt text names the team. A chart is not “bar chart”; its purpose is the finding it shows, so the alt text is the finding.
Examples worth copying
| Context | Weak | Better |
|---|---|---|
| Product photo | Image of a chair |
Oak dining chair with a woven rush seat |
| Team photo on About | Our team |
The four of us outside the studio in Dhaka |
| Chart | Bar chart of results |
Support tickets fell by half after the rewrite |
| Logo linking home | Logo |
WOWStudio, home |
| Icon beside text that already says it | Download icon |
"" (empty, it is decorative) |
| Screenshot in a tutorial | Screenshot |
The Settings screen with 'Enable logging' switched on |
Things to leave out
“Image of” and “picture of”. A screen reader already announces that it is an image. You are spending the listener’s time to tell them something they were just told.
The file name. DSC_00412.jpg read aloud is noise. It is also a specific
check, because it happens constantly when a theme or importer fills the field
automatically.
The caption, repeated. If the text beside the image already says it, the alt text is duplication and the listener hears it twice.
Keywords. Stuffing alt text for search is both useless and rude. Search engines got wise to it a long time ago; screen reader users did not get an opt-out.
How long should it be
Usually one sentence. Occasionally two.
If you need a paragraph, the image is carrying information that belongs in the page itself, where everyone can read it. Put it there and let the alt text be short.
Over-long alt text is its own barrier, and there is a check for it.
Decorative images
An image carrying no information — a divider, a flourish, a spacer — should have
an empty alt attribute: alt="".
That is not a cop-out. It is a deliberate statement that the image can be skipped, and screen readers honour it by saying nothing.
The distinction matters, and tools treat the two cases differently:
| Markup | Reported? | Why |
|---|---|---|
alt="" |
No | Valid and deliberate. The image is decorative. |
No alt attribute |
Yes | The reader is left to guess, and most read the filename aloud. |
So marking a decorative image as decorative is a real fix.
Images that are links
If an image is inside a link and there is no other text in that link, the alt text becomes the link text. It must therefore describe the destination, not the picture.
A logo linking to the home page is WOWStudio, home, not WOWStudio logo.
Doing it in bulk in WordPress
The slow way is opening each media item and filling the field. On a site with a few hundred images that is an afternoon.
Accessibility Remediation has an Images screen that lists every undescribed image in your library with a field beside each one. What you type goes into WordPress’s own alt text field, so it applies everywhere the image is used, works with every theme, and stays behind if you remove the plugin. The details are in Describing images.
It deliberately will not write the text for you. A generated description of an image the machine cannot understand is worse than an empty one, because you would have no way of knowing which descriptions were wrong.
Questions people ask
Does alt text help SEO?
Accurate alt text helps search engines understand images, yes. That is a side effect. Write it for the person listening and the search benefit follows.
What about images loaded by a page builder?
They need alt text too. Builders often store their own copy of the image settings, so check what is actually rendered rather than what is in the media library.
What if I genuinely do not know what an image shows?
Ask whoever added it. If nobody knows why it is on the page, that is useful information about the image.
To find every undescribed image on your site in one pass, the plugin is free on WordPress.org.