Every image deserves to be heard.
Upload an artwork photo, a poster or any image. You get an alt text suggestion to review, written for screen readers.
- Free, no account
- 3 tries per day
- Processed in Europe
- Your image is not stored
Say where the image appears: the description depends on it.
Suggested alt text (to review)
The suggestion will appear here.
This description is a suggestion. You know the image’s role on your page: review before publishing.
What is alt text?
Alt text is a short description of an image. Screen readers read it instead of the image. Blind and low-vision people get the same information. It also shows when the image fails to load. It is one of the oldest accessibility rules of the web.
Not every image needs a description. A decorative image is marked with an empty text. An informative image is described in 1 or 2 short sentences. This is the first criterion of the WCAG accessibility rules.
The WCAG are published by the W3C, the organisation that sets web standards.
An example: before, after
Before
alt="IMG_4032.jpg"
After
alt="A man seen from behind, standing on a rock, looks at a sea of clouds."
The 4 types of images
Not every image needs a description. The right question: what does someone lose without seeing it?
| Image type | What to do | Example |
|---|---|---|
| Informative | Describe what the image conveys. | An artwork photo, a portrait, a simple diagram. |
| Decorative | Leave the alt text empty: alt="". | A background pattern, a mood illustration. |
| Functional | Describe the action, not the image. | A magnifying glass that starts the search: “Search”. |
| Complex | Summarize, then give the details on the page. | A chart, a map, an infographic. |
What a tool cannot do
No tool knows your page. Not ours, not any other.
Good alt text depends on the image’s role. An AI sees the image, not your intent.
The same image is never described the same way twice.
That is why the tool offers a suggestion, never a final text. It also flags images that look decorative and recommends an empty alt.
For a public website, have your pages checked by an accessibility audit.
Frequently asked questions about alt text
When should the alt text stay empty?
When the image is decorative. A decorative image carries no information: a border, a mood illustration, a pattern. In that case, write alt="" with empty quotes. Screen readers then skip the image instead of reading useless text. Our tool flags images that look decorative.
How long should alt text be?
One or two short sentences are enough. Alt text describes the essentials: what the image shows and what it brings to the page. Long descriptions are tiring to listen to. If the image is complex, like a chart, give the key data on the page itself.
Is alt text mandatory?
Yes for images that carry information. It is the first criterion of the international WCAG rules. Many countries apply them to public websites, like the RGAA in France. Beyond the obligation, a site without alt text excludes people who use a screen reader.
Can an AI write good alt text?
An AI describes what it sees well: objects, people, text, colors. It produces a useful suggestion. But it does not know the image’s role on your page. Give it the context, then review: you know what the image should convey.
Should the text inside an image be described?
Yes, always. If an image contains text, that text must appear in the alt text. Otherwise it stays invisible to screen readers. This applies to posters, banners and screenshots. Screen readers cannot read pixels. Better still: avoid putting text inside images at all.
Does alt text help SEO?
Yes, but that is not its first role. Search engines read alt text to understand images. A descriptive, honest text therefore helps your ranking. A list of keywords does the opposite. Write for people, and the ranking will follow. Honesty wins on both fronts.
How can I check the alt texts on my site?
Browse your page with a screen reader, like NVDA, free, or VoiceOver on Mac. You will hear what your visitors hear. Accessibility audit tools also spot images without alt text. The best check remains a test with users with lived experience.
Why this tool is free
Gidmi builds a storytelling tool for museums, galleries and heritage sites. Every image in a tour gets a description written for screen readers, which the team reviews and adjusts. This tool shares that craft: free, no account, no ads.
To discover the creation studio: Create with Gidmi. Accessibility in practice: the Louis Braille Museum study.
The tool does not keep your image. Your image is not used to train an AI model. Processing happens in Europe. The tool allows 3 tries per day, so it can stay free.
Last updated: July 2, 2026