Reviewing a pull request by reading code is slow and error-prone, especially for visual changes. Preview deployments fix this by building every pull request into a live, shareable URL, so reviewers can click through the actual change instead of imagining it. The best part is that the major hosting platforms offer preview deployments free for small teams, which means staging environments no longer need a dedicated server.

This guide explains how preview deployments work, compares the three main free options, and covers the pitfalls, such as preview URLs leaking unfinished work or preview environments needing production data.