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Web App Testing
Use Claude Code to test web applications and find bugs before users do. Automated browser testing with plain English commands.
By Anthropic
Official skill
About
Your signup form worked yesterday. Today a customer emails: "I can't create an account." The bug shipped three days ago. Nobody noticed. Now you're fixing it at 11pm. Instead, describe what should work. Point Claude at your app, tell it what to test, and catch the broken signup before your customers do.
Testing shouldn't require a QA team or a week to set up Selenium. Test in plain English Describe what to test. Claude opens a real browser, clicks through the flow, and tells you what's broken—with screenshots. Catch regressions automatically Every feature gets a test that runs on every push. No more wondering if the last deploy broke something. See exactly what failed Claude walks through your critical paths and reports every failure with the page state when it broke. Know exactly where to fix it.
Best for
- · Catch bugs before they reach production—and before customers report them
- · Write tests in plain English instead of learning a test framework
- · Get screenshots of failures showing exactly what went wrong
- · Build regression tests that run before every deploy
Not for
- · Complex authentication flows with OAuth or 2FA may need additional setup for test credentials
- · Tests run against live URLs—be careful testing actions that modify production data
- · Very dynamic pages with heavy animations may need explicit wait conditions for reliable tests
How to use
- 1Install the SkillDownload the skill file directly, or install via the plugin marketplace. Skills auto-activate when relevant—no manual invocation needed.
- 2Point to Your AppGive Claude a URL—localhost, staging, or production. Tell it what to test in plain English. No test frameworks, no configuration files.
- 3Describe the Expected BehaviorBe specific about what "working" means. Button should redirect here. Form should show this error. Page should load in under 3 seconds.
- 4Review the ResultsClaude runs the test, reports pass or fail, and shows screenshots of what happened. Failed tests include the exact step where things went wrong.
Source
@anthropics on GitHubhttps://github.com/anthropics/skills/tree/main/skills/webapp-testing
Someone else wrote this — read the source, verify it does what it says, and never share a password or API key with it.
Example prompts
Quick smoke test before a deploy
/webapp-testing http://staging.myapp.com Before I deploy, run through: (1) Homepage loads in under 3 seconds, (2) Login works with test@example.com / password123, (3) Dashboard shows recent activity. Screenshot anything that fails.
Testing a specific bug fix
/webapp-testing http://localhost:3000/checkout Customer reported the promo code field doesn't apply discounts. Enter code SAVE20, verify the total drops by 20%, and the success message appears.
Form validation testing
/webapp-testing Try submitting the contact form with: (1) Empty fields, (2) Invalid email format, (3) Valid inputs. Each should show the right error messages or success state.
Cross-browser compatibility check
/webapp-testing Test the checkout flow on Chrome and Firefox. Flag any layout differences or broken functionality between browsers.
Regression testing after a refactor
/webapp-testing I just refactored the auth module. Test: login, logout, password reset request, and session persistence after browser refresh. Nothing should be broken.
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