Automatic diff matching


Covered in this doc

What automatic diff matching is
Criteria for visual changes to be matched

Percy automatically matches and groups snapshots that have the same visual change, saving you time and effort while reviewing builds.

How it works

Criteria for matching diffs

For diffs to be matched, the following criteria must be met:

  • All diffs across all screenshots must have the same geometry, including size but irrespective of page coordinates.
  • Both the baseline screenshots and new screenshots must have the exact same underlying pixels across diffs.
  • Only snapshot comparisons that have the same diff geometry and underlying pixels for each enabled width and browser will be matched.

Approving and requesting changes on groups

When matching diffs are detected, they are grouped together at the top of your snapshot list. All matching changes can be approved with a single click, or you can expand the groupings and approve individual snapshots. The same behavior goes for requesting changes. Please note that requesting changes on all snapshots within a group will also automatically add comments to each of the grouped snapshots.

If you have questions about matching diffs, please feel free to contact support.