Comparison

comparison controls how strict diffs are. Both tolerances default to {} (exact):

• numericTolerance (absolute / relative) loosens metric and numeric diffs — numbers within the epsilon compare as equal. Useful for accessibility values and performance metrics that jitter run to run.
• pixelTolerance (maxChangedRatio / perChannelThreshold) loosens screenshot diffs. maxChangedRatio is the fraction of pixels (0–1) allowed to differ; perChannelThreshold is the per-channel 0–255 delta tolerated before a pixel counts as changed (absorbs anti-aliasing noise).

When a screenshot change is within pixelTolerance, the snapshot passes; failing results include a pixel summary (changed pixels, ratio, dimensions) in the JSON report.

See the schema for the field reference.