Preview Deployments: A Live URL for Every Branch
This is Vercel's single most distinctive feature — every branch and pull request gets its own real, live, shareable deployment automatically, not just a local preview only you can see.
Push a branch, and Vercel deploys it to a unique URL automatically, with zero configuration required beyond the initial GitHub connection (from the Welcome course). This deployment is fully live and functional — not a static mockup, the actual application running against whatever it's configured to connect to.
Every Preview Deployment gets posted directly on the GitHub Pull Request — a comment (or a status check) with the live URL appears automatically, so anyone reviewing the PR can click through and interact with the real, running change before approving it.
This transforms code review from "read the diff" to "read the diff AND actually use the change." A reviewer can click a button, submit a form, or navigate through the actual updated application — catching UX issues, visual regressions, or behavioral problems that a diff alone would never surface.
Preview Deployments are genuinely isolated from Production, each with their own URL and (as covered in the next lesson) their own environment variable scope — testing in Preview carries none of the risk of touching real production data or traffic.
Non-technical stakeholders can review real, running changes without needing to read code at all. Share a Preview URL with a designer, a product manager, or a client — they interact with the actual application, not a code diff they might not be able to parse.
Why this matters for you
Preview Deployments are the single feature that most changes how a team actually reviews changes — this course spends real depth here because it's genuinely central to how Vercel is meant to be used, not a peripheral nice-to-have.
▶️ Before the next lesson
Create a new branch on a project deployed to Vercel, push it, and open a Pull Request — confirm Vercel automatically posts a Preview Deployment link on the PR.