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Coding Workflows

Web app testing

Lets Claude open your site in a real browser, click through it and screenshot problems.

Open sourceBy Anthropic
View source

What is it?

Gives Claude a tested way to drive a web browser against the site it is building: start the local server, load pages, fill in forms, click buttons, capture screenshots and read the browser's error log. It uses Playwright, a widely used browser automation tool, behind the scenes.

Without it, Claude says the feature works because the code looks right. With it, Claude checks by actually using the site, which catches the broken button or missing field before you do.

Install in Claude Code

In Claude Code run /plugin marketplace add anthropics/skills, then /plugin install example-skills@anthropic-agent-skills. That bundle includes this skill alongside Anthropic's other example skills.

Try this prompt

Paste into Claude Code
Start my site locally, go through the signup form as a new customer, and show me screenshots of anything that looks broken on mobile.

Who it's for

Anyone building a site or app with Claude Code who wants proof it works, not a promise.

Best for

  • Checking forms and checkouts
  • Mobile layout checks
  • Reproducing a reported bug
  • Before-and-after screenshots

Why it made the list

Seeing is better than assuming, and this is the simplest way to make Claude look.

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