Issue Grouping

A fingerprint is a way to uniquely identify an event, and all events have one. Events with the same fingerprint are grouped together into an issue.

By default, Sentry will run one of our built-in grouping algorithms to generate an event fingerprint based on information available within the event. The available information and the grouping algorithms vary by event type. Sentry fingerprints error events based on information like stacktrace, exception, and message. Transaction events are fingerprinted by their spans.

Default Error Grouping Algorithms

Each time default error grouping behavior is modified, Sentry releases it as a new version, which is only applied to new events going forward. As a result, modifications to the default behavior do not affect the grouping of existing issues.

When you create a Sentry project, the most recent version of the error grouping algorithm is automatically selected. This ensures that grouping behavior is consistent within a project.

All versions consider the fingerprint first, the stack trace next, then the exception, and then finally the message.

To see how an issue was grouped, go to its Issue Details page and scroll down to "Event Grouping Information". There, you'll see if it was grouped by a fingerprint, stack trace, exception, or message.

Grouping by Built-In Fingerprinting Rules

Some kinds of errors, like chunk load errors and hydration errors, often have various different error types, values, or transaction messages that may result in separate but similar issues. To better handle these cases, Sentry maintains a set of built-in fingerprinting rules to better group such errors.

Issues grouped by Sentry's built-in fingerprinting rules will list "Sentry Defined Fingerprint" in the "Event Grouping Information" at the bottom of the Issue Details page.