Sentry

What is Sentry?

Sentry is an error monitoring and performance tracking platform. When something breaks in your application, Sentry captures it — the full stack trace, the user's browser and OS, the URL they were on, the sequence of actions that led to the error, and any custom context you've tagged. It turns vague bug reports into actionable information.

Error tracking

The SDK integrates into your application and intercepts unhandled exceptions automatically. Errors are grouped into issues by their fingerprint, so you see how many times a particular error has occurred rather than a flood of individual events. Each issue shows affected users, first and last seen dates, and a graph of occurrences over time. You can assign issues, mark them as resolved, and configure alerts when new ones appear.

Performance monitoring

Beyond errors, Sentry can trace request performance across your stack. You can see which transactions are slow, what database queries are running inside them, and where time is being spent. Distributed tracing connects a frontend request to the backend services it touches, which is useful for understanding latency in multi-service architectures.

Release tracking

Sentry tracks which version of your code each error occurred in. If you deploy a release and a new error spikes, it's immediately visible which commit introduced it. You can also mark errors as resolved in a specific release, and Sentry will reopen the issue if the same error appears in a later version.

Pricing

Sentry has a generous free tier that's sufficient for many small applications. Paid plans scale based on event volume and add features like increased data retention, SSO, and advanced integrations. The hosted version is the easiest to get started with; a self-hosted option also exists.