Baseline builds
The baseline is the last approved build on your base branch. Learn how Snapvisor picks the reference build and resolves the base branch for every comparison.
Every comparison needs something to compare against. The baseline is the last approved build on your base branch — the reference Snapvisor diffs new screenshots against.
What the baseline is
When a build runs, Snapvisor looks for an approved build to use as the reference. It walks your Git history to find the first ancestor commit on the base branch that has an approved build, and diffs against that. Only the differences are surfaced for review.
How the base branch is chosen
Snapvisor resolves the base branch in this order:
- The pull request's base branch, when the build runs on a PR.
- Otherwise a custom default base branch you set in project settings.
- Otherwise the repository's own default branch, falling back to
main.
# tell Snapvisor which branch holds the approved baseline
# (defaults to the repository's default branch, else "main")When there is no baseline
The very first build on a branch has nothing to compare against, so it becomes the reference and is approved automatically. If a later build can't find an approved ancestor — for example after a force-push — Snapvisor tells you it couldn't match a commit, and you may need to rebase so history lines up again.
Branches you mark as auto-approved skip manual review and set their own baseline. See monitoring mode.
Migrate from Lost Pixel
Move a lostpixel.config.js suite to Snapvisor - how shots, masks, breakpoints, and thresholds translate, and why baselines stop living in your git repository.
Monitoring mode
Auto-approve branches so their builds set a success check without manual review. Learn how monitoring mode differs from the CI review workflow in Snapvisor.