demo · v130
Too-aggressive scoping
Attribution scopes are designed to prevent wrong-campaign attribution — but you can over-correct. If source scopes are too narrow or the trigger sends a similar-but-not-identical scope, Chrome 130 filters out every candidate instead of attributing to the closest match. This demo shows the scope-miss scenario side-by-side with pre-130 behaviour and an omitted-trigger control.
Sources registered (ad impressions)
Conversion trigger
Leave blank to omit the trigger field, which keeps all sources eligible. Type a non-empty scope to require an exact source-scope match.
Pre-Chrome 130 (no scopes)
Chrome 130+ (with scopes)
when over-scoping hurts
Attribution scopes solve the wrong-campaign problem, but they also add a new risk: if the trigger’s scope doesn’t match any registered source scope, Chrome 130 does not attribute at all. Pre-130, the browser would fall back to the most-recent-source heuristic and always report something.
Common causes of scope misses:
- Trigger fires with a campaign ID that was never added to the source registration
- Trigger sends shorthand, such as
campaign-a, when the source usedcampaign-a-2025-q1 - Typo mismatch between source and trigger scope strings
- Source scope was truncated due to a tight
limit
Omitting the trigger attribution_scopes field is different: Chrome leaves sources eligible because no trigger-side scope filter was requested. Use the third preset as that control case.