AI Describe (alt text)

AI Describe reads an image and writes a description of it. Most images on the web have no alt text and the usual reason is not indifference, it is a hundred images and no time; a first draft in a second changes that arithmetic. The tool is listed as AI Alt Text on the tools pages and appears as AI Describe in the image editor — same thing.

This is the one with no fallback

The other two model-backed tools keep working when you decline their download, because a classical sharpening pipeline is a genuinely useful weaker answer. There is no classical shortcut for describing a photograph in words: it requires a model that has seen photographs. So declining here leaves the tool unable to run, and it says so plainly rather than producing something worthless.

Nothing downloads until you allow it. The consent gate names the size and what happens if you decline, your answer is stored on this device, and you can change it later from the same line of text — the flow described in why AI tools download a model once.

One caveat on the number in that dialog. It quotes ~120 MB, which is the size of the ViT-GPT2 captioner. In practice the worker tries the richer Florence-2 model first and only falls back to ViT-GPT2 if Florence-2 will not load or run, and Florence-2 is the larger fetch — its loader reports roughly 230 MB. Either way it is a one-time download that caches afterwards, but a first run can pull more than the dialog quotes.

Styles

Five styles, each a different post-process over the same caption:

• Alt text (the default) — one short sentence for a screen reader, capped at twelve words. The brevity is the point.
• Scene — subject, environment and lighting mood.
• Product — subject, material and distinctive features, for a listing.
• Objects — a comma-separated list, most prominent first.
• Social caption — one friendly sentence.

Scene and Product ask the model for a longer, more detailed caption. Alt text never does, deliberately.

There is also a quiet escalation for documents: a cheap local pixel check flags text-dense images — screenshots, scans, anything that is mostly ink on paper — and upgrades them to the detailed caption, because the brief one tends to come back as something like "a computer screen with a lot of numbers". That upgrade is skipped for alt text, where screen-reader brevity wins.

Where it is weakest

• Charts, diagrams and dense screenshots. Anything whose meaning lives in its text or its axes. The model describes what it recognises, and a bar chart looks like a bar chart to it.
• Text in the image. Often missed or misread. Check it, and put it in the alt text yourself.
• Anything requiring knowledge. It does not know a name, a brand, a place, or which detail is the reason the image is on your page.
• Other languages. It writes English.

Treat the output as a draft

Alt text is not a description of an image. It is a replacement for the image, in the context of the page it sits on. The same photograph of a bridge wants "the Clifton Suspension Bridge from the Somerset side" in an article about Bristol and "a suspension bridge at dusk" in a piece about lighting. A model can only produce the second.

The result appears in an editable box for exactly this reason. Before you ship it:

• Add what only you know — names, places, brands, and the detail that made you use this image.
• Cut what the page already says. Alt text that repeats the caption underneath makes a screen reader say everything twice.
• Do not start with "image of". Screen readers already announce that it is an image.
• Purely decorative images take empty alt (alt=""), not a description. Describing a background flourish is noise, not access.

Limits

• No download, no tool. There is no degraded mode.
• English only, and there is no language setting.
• JPEG, PNG or WebP in, up to 32 MB. Text out, with a Copy button and the token count.
• The model is deterministic and takes no prompt, so there is no way to ask it a question about the image from this tool.
• Everything runs in this tab. Neither the image nor the generated text is sent anywhere.

In the image editor

The tool is in the image editor's launcher, under AI Tools, as AI Describe. Its output is text, so it is reported back to you rather than applied to the canvas, and it is not offered in the video editor. Because there is no fallback, running it in the editor before answering the download question fails with a message pointing you at the tool page to answer it.

Related

• AI Face Restore
• AI Deblur — sharpen a soft image first; a clearer image gets a better description
• Image metadata remover — strip location and camera data before publishing
• Why AI tools download a model once