[opensourcedex]

Sentry is a free, open source monitoring & observability project written in Python and released under a custom open-source licence. It has 44,792 GitHub stars, 4,854 forks and 2,265 open issues, and was last pushed 5 hours ago. On this registry it ranks #6 of 97 tracked projects in Monitoring & Observability, and is listed as an open source replacement for 1 paid product, with 5 head-to-head comparisons available. It gained 24 stars over the last 6 tracked days.

Sentry — Real-time error tracking and performance monitoring

What is Sentry?

What it is

Sentry is an open-source debugging platform for detecting, tracing, and fixing software issues in real time. It lives in the developer infrastructure ecosystem and provides error tracking and performance monitoring across languages, frameworks, and runtime environments.

Sentry solves the problem of fragmented debugging workflows by unifying crash reporting, exception logging, and application performance monitoring into a single platform. Developers receive actionable context—such as stack traces, user data, environment details, and release info—without switching between tools or waiting for log aggregation cycles.

Key capabilities

  • Real-time error ingestion and deduplication for exceptions and crashes across client and server workloads
  • Distributed tracing with span-level performance metrics and latency breakdowns
  • Release health tracking, including error rate and session health per version
  • Customizable alerting rules based on error frequency, performance degradation, or session impact
  • Integration with CI/CD pipelines for automatic release correlation and blame assignment
  • Support for Content Security Policy (CSP) report ingestion for frontend security monitoring
  • Native SDKs for 20+ languages and frameworks, including JavaScript, Python, Go, Java, Rust, and Unity

Who uses it and how

  • Web application teams use JavaScript and Python SDKs to capture unhandled exceptions and report backend errors from Django or Flask apps
  • Mobile developers integrate React Native, iOS, or Android SDKs to collect crash reports and device context from production builds
  • DevOps teams deploy the self-hosted Sentry backend to maintain data sovereignty and integrate with internal identity providers
  • SaaS companies leverage performance monitoring to detect regressions in API latency or frontend load times before users notice
  • Open-source projects use the fair-source model to contribute improvements while avoiding vendor lock-in

Getting started

Install the Sentry server via Docker using getsentry/sentry image, or use the hosted option at https://sentry.io. SDKs are distributed via language-native package managers (e.g., pip, npm, gem, composer).

When to use it — and when not to

Sentry replaces paid error-tracking and APM services with comparable data fidelity, but self-hosting requires managing PostgreSQL, Redis, and optionally SMTP or object storage for attachments. It is unsuitable for teams needing fully managed infrastructure without operational overhead or those requiring built-in log aggregation unrelated to errors. The open-core model means advanced features like custom event retention or SAML SSO are only available in the hosted tier.

project readme (upstream, from github) — read inline

Sentry

Users and logs provide clues. Sentry provides answers.

What's Sentry?

Sentry is the debugging platform that helps every developer detect, trace, and fix issues. Code breaks, fix it faster.

Official Sentry SDKs

Resources

Frequently asked questions

Is Sentry free to use?

Sentry is open source. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does Sentry do?

Real-time error tracking and performance monitoring

What is Sentry written in?

Sentry is primarily written in Python. Its source is publicly available at https://github.com/getsentry/sentry, and it has 44,792 GitHub stars.

What is a good open source alternative to Sentry (hosted)?

Sentry is one of the open source options listed as an alternative to Sentry (hosted). Compare licences, stars and activity side by side on the Sentry profile.