Browser QA — Automated Visual Testing & Interaction When to Use After deploying a feature to staging/preview When you need to verify UI behavior across pages Before shipping — confirm layouts, forms, interactions actually work When reviewing PRs that touch frontend code Accessibility audits and responsive testing How It Works Uses the browser automation MCP (claude-in-chrome, Playwright, or Puppeteer) to interact with live pages like a real user. Phase 1: Smoke Test 1. Navigate to target URL 2. Check for console errors (filter noise: analytics, third-party) 3. Verify no 4xx/5xx in network requests 4. Screenshot above-the-fold on desktop + mobile viewport 5. Check Core Web Vitals: LCP < 2.5s, CLS < 0.1, INP < 200ms Phase 2: Interaction Test 1. Click every nav link — verify no dead links 2. Submit forms with valid data — verify success state 3. Submit forms with invalid data — verify error state 4. Test auth flow: login → protected page → logout 5. Test critical user journeys (checkout, onboarding, search) Phase 3: Visual Regression 1. Screenshot key pages at 3 breakpoints (375px, 768px, 1440px) 2. Compare against baseline screenshots (if stored) 3. Flag layout shifts > 5px, missing elements, overflow 4. Check dark mode if applicable Phase 4: Accessibility 1. Run axe-core or equivalent on each page 2. Flag WCAG AA violations (contrast, labels, focus order) 3. Verify keyboard navigation works end-to-end 4. Check screen reader landmarks Output Format
QA Report — [URL] — [timestamp]
Smoke Test
Console errors: 0 critical, 2 warnings (analytics noise)
Network: all 200/304, no failures
Core Web Vitals: LCP 1.2s ✓, CLS 0.02 ✓, INP 89ms ✓
Interactions
[✓] Nav links: 12/12 working
[✗] Contact form: missing error state for invalid email
[✓] Auth flow: login/logout working
Visual
[✗] Hero section overflows on 375px viewport
[✓] Dark mode: all pages consistent
Accessibility
2 AA violations: missing alt text on hero image, low contrast on footer links
Verdict: SHIP WITH FIXES (2 issues, 0 blockers) Integration Works with any browser MCP: mChild__claude-in-chrome__ tools (preferred — uses your actual Chrome) Playwright via mcp__browserbase__ Direct Puppeteer scripts Pair with /canary-watch for post-deploy monitoring.