Claude alt text generator

The job

What the Claude alt text generator is for

You have a page, a post or a product listing with images that have no alt attribute. This turns your own short description of each one into a line you can paste into the attribute. It writes; you supply the context and you check the result.

There is no file picker in this workflow. The route sends text to our server and gets text back, so what you paste is a description, not a photograph. That gives you 5 runs per rolling 24 hours, no signup step, and an input of 1 to 12,000 characters, which is enough room to describe several images in one go if you keep each one to a line or two.

The loop

How to generate alt text in three steps

Repeat this per image. It goes faster than it reads.

Step 1

Write two things: what is in the image, and what job it is doing on the page. The second half is the one people skip and the one that changes the output.

Step 2

Run it. If the house style is short and blunt, or the audience is technical, put that in the instruction box, because your instruction is added to the brief the server works from.

Step 3

Look at the picture and the sentence side by side, fix anything the description got wrong, then paste it into the alt attribute.

Before you start

Sort the images first, then generate

Half the work on a real page is deciding which images need a sentence at all. Do this pass first and the generating part shrinks.

Decorative

Dividers, background textures, an icon next to a label that already says the word. These get alt="" and no description. Do not spend a run on them.

Informative

Photographs, screenshots, anything the surrounding text relies on. These are what the generator is for.

Charts and diagrams

One sentence in the attribute naming the type and the trend, with the real numbers written into the body copy underneath.

Images made of words

A quote card, a pricing table screenshot, a poster. The words in the picture have to reach the attribute or the body text, because a screen reader cannot read pixels.

Input quality

What to type into the alt text generator

The output tracks the input closely, so the description you write is the lever. Four things are worth including and one is worth leaving out.

The subject, counted and named

Not runners training. Four women doing lunges beside a running track.

The purpose

Illustrating a news story, proving a product detail, showing a step in a tutorial. The same photograph earns different alt text in each.

Anything the body text already says

Mention it so the generator can avoid repeating it, because a screen reader user hears the caption and the alt text back to back.

Leave out your opinion

Stylish, striking and beautiful describe how you feel about the image. They tell a listener nothing about what is in it.

Length

How long should the alt text be?

Work to 125 characters. The number comes from screen reader behaviour, which is widely reported to chunk long announcements around there, so an over-long attribute can be cut for the person relying on it. It is a convention rather than a standard: WCAG itself sets no character limit.

When the image genuinely carries more than that, the answer is not a longer attribute. Put a short line in the alt text and the detail in the paragraph next to the image, where everyone gets it. That is also the honest answer for the chart case, and it is why the triage pass above is worth doing before you start writing.

The objection

Is alt text an accessibility job or an SEO job?

Both, in that order. It gives a crawler words where there was only an image file, which is a real benefit. But we will not put a figure on it, and neither will the tools that sell on it: Ahrefs phrases its own version as 'potentially driving more organic traffic'.

The practical consequence for your workflow is that you do not need a separate SEO pass. A description that is accurate and specific already contains the words that matter. Adding keywords on top of an accurate description makes it worse for a listener without making it better for anything else.

Where it stops

What this alt text generator does not include

No upload, no bulk queue, no CMS plugin, no browser extension and no API. AltText.ai covers all of that, with bulk CSV import, Dropbox and Cloudinary sources, a WordPress and Shopify integration and a site scan that reads 25 pages on its free tier. This route is one text box and one run at a time.

It also will not tell you which images on your site are missing alt attributes. Your CMS or an accessibility checker does that part. Bring the list here, describe them one at a time, and paste the results back. And no tool, this one included, can certify WCAG or ADA compliance, because whether a description serves the same purpose as the image depends on a page it never sees.