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 (codex-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__codex-in-chrome__* tools (preferred — uses your actual Chrome)
• Playwright via mcp__browserbase__*
• Direct Puppeteer scripts

Pair with /canary-watch for post-deploy monitoring.