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Preview & Production Deployments
Every non-production branch/PR gets a preview deployment — a full, live copy of the app for that change, the feature most teams adopt Vercel for.
Previews
- Per-PR URLs — each push updates the preview; the URL is stable per branch and posted to the PR.
- Preview deployment suffix — customize the preview domain (e.g. use your own domain for previews instead of
*.vercel.app). - Sharing — previews can be shared with stakeholders; combine with deployment protection (password/SSO) for private previews, or sharable links for external reviewers.
- Preview environment variables — separate values for preview vs production (environment-variables).
Promotion to production
A preview that's been validated can be promoted to production without rebuilding — the exact artifact reviewers approved becomes production, eliminating "works in preview, breaks in prod." The inverse is instant rollback.
Skew protection
During a deploy, users mid-session might have an old client talking to a new backend (or vice versa) — version skew. Skew protection routes a client's requests to the deployment version it loaded, preventing broken states during rollouts. Essential for SPAs and apps with client/server contracts that change between deploys.
Rolling releases
Vercel also supports gradual rolling releases (shifting traffic to a new production deployment in stages) for safer launches — see docs-catalog.