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Vizzly Docs

Baselines

A baseline is the reference screenshot Vizzly compares against.

If a screenshot does not match an existing baseline, it shows up as new or missing instead of changed.

How matching works

By default, Vizzly matches screenshots using:

  • screenshot name
  • captured image width
  • browser, if present

That is why a renamed screenshot or a different captured image width usually creates a new baseline path instead of a changed comparison.

Baseline signature properties

You can add extra properties to the matching signature when one screenshot name needs separate baselines for different variants.

Good examples:

  • theme
  • device
  • locale

Use this when dashboard in dark mode should not share a baseline with dashboard in light mode.

Baseline modes

Git mode

This is the default and the mode most teams want.

Vizzly tries to find the right baseline from your git history:

  1. use the latest earlier approved build on the same branch
  2. otherwise use an approved build at common_ancestor_sha, if the build includes one
  3. otherwise ask GitHub for the merge base, if GitHub is connected
  4. otherwise use the latest earlier approved build on the baseline branch

Vizzly can skip a recent candidate when its screenshot count suggests the build is incomplete.

Manual branch mode

Each branch gets its own manually selected baseline.

Use this when branches need to evolve independently for a while.

Manual mode

One fixed build acts as the baseline for every branch until you change it.

Use this when you want a stable, frozen reference point.

Which builds can become baselines

Vizzly uses completed, approved builds as baselines. Pending, rejected, failed, and identical-only builds are not baseline candidates.

Common issues

A screenshot shows up as new

Check whether the name, captured image width, browser, or configured signature properties changed.

Git mode did not find the baseline you expected

Check:

  • the configured baseline branch
  • whether that branch has an earlier approved build
  • whether the build has enough screenshots to be a useful baseline

You cannot mark a build as baseline

The build must be completed and approved, and you need permission to manage the project.

Next steps