Guide · Agent skill
How to use the Image Alt Text Checker agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The alt-text skill teaches an AI agent to review the images in a web project and check whether their alt text is meaningful to screen reader users. It is aimed at front-end developers, designers and content editors who want to find missing or weak alt text before a launch or accessibility review. After reading this guide you will know what the skill does, how to install it, how to ask for it in plain language, and where its limits are.
Image Alt Text Checkerthedaviddias/Front-End-Checklist · MIT Download the skill Quick start
- 1Download the ZIP. Get the alt-text skill ZIP from the skill page on this site.
- 2Unzip into a skills folder. Extract it into ~/.claude/skills/ for personal use, or into a project's .claude/skills/ folder.
- 3Or upload in the Claude apps. In Settings → Capabilities → Skills, upload the ZIP instead.
- 4Ask for a review. Name the page or folder and ask the agent to check alt text in plain words.
- 5Review the rewrites. Check each suggested alt value against the actual image before accepting it.
- 6Confirm in DevTools. Reload the page and inspect the <img> elements to verify the new alt attributes.
What the alt-text skill makes the agent do
Alt text is the short description a screen reader reads aloud in place of an image. Without it, people who are blind or have low vision get no information about the image. Missing alt text also fails WCAG 2.1 Success Criterion 1.1.1, a Level A requirement.
When the skill is active, the agent scans the <img> elements in your code and checks several things: whether every image has an alt attribute, whether decorative images use alt="", whether informative images describe their meaning rather than their file name, whether linked images describe the destination, and whether images of text repeat the text. It flags alt values that match the filename or are generic, such as alt="image" or alt="photo".
- Flags images with no alt attribute
- Flags alt values that repeat the filename or are generic
- Rewrites alt text to describe purpose and meaning
- Uses alt="" for decorative images
- Reviews image files, sizing and loading behaviour in code
- Explains how to confirm the fix in browser DevTools
Install the alt-text skill
Download the alt-text ZIP from the skill page on this site. Then choose one of the two install locations below.
For a personal setup available across your projects, unzip the download into ~/.claude/skills/. For a single project, unzip it into that project's .claude/skills/ folder. In the Claude apps you can instead upload the ZIP under Settings → Capabilities → Skills.
After unzipping, the skill folder should contain SKILL.md and references/rule.md.
- Personal: ~/.claude/skills/
- Project only: .claude/skills/ inside your project
- Claude apps: Settings → Capabilities → Skills, then upload the ZIP
Trigger the skill with natural requests
You do not need a special command. The skill's description tells the agent when to use it, so ask for what you want in ordinary words. Naming the image-related task or the files helps the agent pick the right skill.
Good requests name a scope: a page, a component, or a folder. The more specific you are, the more useful the review.
- Check the alt text on the homepage template and suggest fixes.
- Review every <img> in src/components/ for missing or generic alt attributes.
- Which images on this page are decorative and should use alt=""?
- Rewrite the alt text for the product cards in this project so it describes purpose.
See what a good result looks like
The reference material shows the typical problems the skill is built to catch. A chart with no alt attribute, a chart whose alt is its filename, and a chart with alt="chart" all fail. A good version says what the image conveys, for example a bar chart showing a revenue increase in a given quarter.
For complex images such as charts or infographics, the skill suggests a short alt plus a longer description, linked with aria-describedby or a visible caption. For images of text, the text is copied verbatim into alt.
<img src="revenue-chart.png" alt="Bar chart showing Q3 2024 revenue increase">Check the result in browser DevTools
The skill explains how to confirm a fix in DevTools. After the agent changes the markup, reload the page in your browser, open the developer tools, and inspect the affected <img> elements to confirm the alt attribute now has the value the agent proposed.
Re-run the review after your changes so the agent can confirm nothing else was missed.
Safety notes and requirements
The source lists no requirements for this skill. It does not run scripts and does not use the network, so the agent works from the files you give it in your project.
Because the agent judges alt text by reading code and file names, it cannot see the images. Descriptions of actual image content may be guesses, so a person should check every rewrite against the image before it ships.
- Requires: nothing listed
- Runs scripts: no
- Uses network: no
- Files: SKILL.md and references/rule.md
What people use it for
- Auditing a site's templates for WCAG 1.1.1 before launch
- Finding decorative images that should use alt=""
- Rewriting filename-style alt values in a component library
- Giving a content editor clearer alt text for a landing page
- Preparing a list of images for a human accessibility review
Frequently asked questions
How do I install the alt-text agent skill?
Download the alt-text ZIP from this site, then unzip it into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder. In the Claude apps you can upload the ZIP under Settings → Capabilities → Skills instead.
Does the alt-text skill require anything else to run?
The source lists no requirements. It does not run scripts and does not use the network.
Is the alt-text skill free?
The skill is released under the MIT licence. The source does not state pricing for it, so check the licence file in the source repository for the terms.
Can the skill scan a whole website automatically?
It is not designed for unattended site-wide scanning. The agent reads code and file names and can misjudge context, so a developer should review its output.
Why does the skill need a human to check alt text?
The agent cannot see the images and works from markup and file names. Its descriptions of image content may be guesses, so each rewrite should be checked against the picture.
How is this different from an automated accessibility scanner?
The source does not compare it with other tools. In practice, this skill reads your code and suggests rewrites for a developer to review, rather than crawling a live site and reporting results automatically.
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Our verdict
Use this skill if you are a developer, designer or content editor who wants an agent to review alt text in your code and propose clearer wording tied to WCAG 1.1.1. Pick a different approach if you need unattended scanning of a whole site or cannot have a person check the descriptions against the images.
Download the skill