Next.js & React Pre-Launch Checklist
Full-Stack Web App QA Guide
Modern React and Next.js applications build fast, but runtime edge-cases like SSR hydration mismatches, auth redirect loops, and unhandled async mutations often slip into production.
Top 3 Silent Failure Modes in Next.js & React Apps
Auth Callback & Redirect URI Mismatches
When deploying to custom domains, the OAuth redirect URI often defaults to localhost or staging URLs, causing login flows to fail silently in production.
Unhandled React Query / Async State
Components trying to access nested properties on data before Supabase queries resolve, resulting in 'Cannot read properties of undefined' console errors.
Environment Variable Leaks & Missing Secrets
VITE_ prefix omissions on client-side env vars cause runtime reference errors, while backend service keys can be inadvertently exposed in client bundles.
Pre-Launch Verification Checklist
- ✓Verify home and dashboard load without any red console errors in DevTools
- ✓Check that all internal navigation links point to valid client routes, not 404s
- ✓Test Supabase sign-up and sign-in flows with email magic link and Google OAuth
- ✓Ensure all images render with proper alt text and no broken asset URLs
- ✓Confirm that responsive mobile layout does not overflow horizontally
Automate this entire audit in 30 seconds
Don't manually click every link or inspect every console tab. PreLaunchQA loads your Next.js & React app in a real Chromium browser and gives you raw evidence of every issue.