One of these counts things and the other explains them. Prometheus scrapes numeric time series from your services, stores them, and lets you query with PromQL and alert through Alertmanager. It is the de facto standard for Kubernetes monitoring and it is free. Sentry sits inside the application and captures the exception itself, with a full stack trace, source maps for frontend JavaScript, and Autofix proposing a change. Ask Prometheus how many 500s you served in the last hour and it answers instantly. Ask it which line threw and it has nothing to say. Sentry is the reverse: precise about a single failure, indifferent to the aggregate shape of your traffic.
Treat this as an ordering question rather than a choice. If you are running Kubernetes and have no metrics at all, Prometheus first: free, self-hostable, and everything in that ecosystem already speaks its format. If you have metrics and your engineers are still reconstructing stack traces from log lines, add Sentry, which is free to 5,000 errors and around $26 a month for Team. The gaps to plan around are clear enough. Prometheus carries real operational overhead, was never designed for end-user or API uptime checks, and needs extra components for long-term storage. Sentry has no synthetic monitoring, and it produces alert fatigue if nobody tunes it.
Application error monitoring and performance management
Pricing: Developer (Free - 5k errors), Team from ~$26/mo, Business from ~$80/mo
Founded: 2012
Best for: Developers, Frontend Teams, Backend Engineers
Open-source metrics monitoring and alerting toolkit
Pricing: Free and open source
Founded: 2012
Best for: DevOps, SREs, Platform Engineers
4 of 18 capabilities separate these two. Those come first.
| Feature | Sentry | Prometheus |
|---|---|---|
| Where they differ (4) | ||
| Real User Monitoring | Sentry: yes | Prometheus: no |
| AI-Powered | Sentry: yes | Prometheus: no |
| Slack Integration | Sentry: yes | Prometheus: no |
| Open Source | Sentry: no | Prometheus: yes |
| Both tools have (7) | ||
| Uptime Monitoring | Sentry: yes | Prometheus: yes |
| Alerting | Sentry: yes | Prometheus: yes |
| CI/CD Integration | Sentry: yes | Prometheus: yes |
| On-Premise / Self-Host | Sentry: yes | Prometheus: yes |
| Free Tier | Sentry: yes | Prometheus: yes |
| API Access | Sentry: yes | Prometheus: yes |
| Dashboards | Sentry: yes | Prometheus: yes |
| Neither tool has (7) | ||
| Synthetic Monitoring | Sentry: no | Prometheus: no |
| API & Browser Testing | Sentry: no | Prometheus: no |
| Self-Healing Tests | Sentry: no | Prometheus: no |
| Multi-Location Checks | Sentry: no | Prometheus: no |
| SSL Monitoring | Sentry: no | Prometheus: no |
| Status Page | Sentry: no | Prometheus: no |
| Incident Management | Sentry: no | Prometheus: no |
Pros
Cons
Pros
Cons
Sentry is application error monitoring and performance management, while Prometheus is open-source metrics monitoring and alerting toolkit. Sentry adds Real User Monitoring, AI-Powered, and Slack Integration on top of the shared feature set. Prometheus brings Open Source that Sentry does not.
Sentry pricing: Developer (Free - 5k errors), Team from ~$26/mo, Business from ~$80/mo. Prometheus pricing: Free and open source. Evaluate against your check volume and team size; entry pricing rarely reflects total cost at scale.
Sentry is designed with Developers, Frontend Teams, and Backend Engineers in mind, whereas Prometheus targets DevOps, SREs, and Platform Engineers. If your team matches the former profile, Sentry is usually the closer fit.
No. It does a different job. Error trackers tell you an exception fired. They can't see the failures that never throw: a checkout that silently breaks, an expired SSL certificate, a page that returns 200 and renders blank. ObserveOne monitors those user-facing journeys in production; teams run it alongside an error tracker, not instead of one.
Error trackers tell you an exception fired. They can't see the failures that never throw: a checkout that silently breaks, an expired SSL certificate, a page that returns 200 and renders blank. ObserveOne monitors those user-facing journeys in production; teams run it alongside an error tracker, not instead of one. The free tier covers enough to try it on one critical journey.
Each tool has its own alternatives page too, not just this matchup.