Cross-browser, cross-platform, and cross-device compatibility testing ensuring consistent experience across environments. Use when validating browser support, testing responsive design, or ensuring platform compatibility.

Compatibility Testing Browser engine Browser driven checks (viewport emulation, responsive validation, cross browser screenshots) should go through the qe browser fleet skill ( .claude/skills/qe browser/ ). Vibium is installed by aqe init . Quick reference: Cross browser (Firefox/Safari) still requires Playwright or a cloud device farm today — Vibium's BiDi backend is Chrome only at v26.3.x. <default to action When validating cross browser/platform compatibility: 1. DEFINE browser matrix (cover 95%+ of users) 2. TEST responsive breakpoints (mobile, tablet, desktop) 3. RUN in parallel across browsers/devices 4. USE cloud services for device coverage (BrowserStack, Sauce Labs) 5. COMPARE visual screenshots across platforms Quick Compatibility Checklist: Chrome, Firefox, Safari, Edge (latest + N 1) Mobile Safari (iOS), Mobile Chrome (Android) Screen sizes: 320px, 768px, 1920px Test on actual target devices for critical flows Critical Success Factors: Users access from 100+ browser/device combinations Test where users are, not where you develop Cloud testing reduces 10 hours to 15 minutes </default to action Quick Reference Card When to Use Before release After CSS/layout changes Launching in new markets Responsive design validation Cross Browser with Playwright Cloud Testing Integration Agent Driven Compatibility Testing Agent Coordination Hints Memory Namespace Fleet Coordination Related Skills [mobile testing](../mobile testing/) Mobile specific testing [visual testing advanced](../visual testing advanced/) Visual regression [accessibility testing](../accessibility testing/) Cross platform a11y Remember Cover 95%+ of your user base. Use analytics to identify actual browser/device usage. Don't waste time on browsers nobody uses. With Agents: Agents orchestrate parallel cross browser testing across cloud platforms. qe visual tester catches visual inconsistencies across platforms automatically.

compatibility-testing