Choose Sentry if your main need is catching and fixing application errors, with traces, replays and an AI agent called Seer that suggests fixes, and you'd like a free plan or the option to self-host. Choose Datadog if you need full observability across infrastructure, logs, security and apps on one platform, with error tracking as one part of it. Sentry's free Developer plan covers one user; Datadog's free Infrastructure tier covers up to 5 hosts with one day of metric retention.
Both promise to tell you why your app broke, so I read Sentry's plans, product, about and self-hosting pages and Datadog's plans and error tracking pages and compared them side by side.
Sentry and Datadog at a glance
| Sentry | Datadog | |
|---|---|---|
| Focus | Application errors and debugging | Observability across your whole stack |
| Free tier | Developer plan, one user | Infrastructure Free, up to 5 hosts, 1-day retention |
| Error grouping | Errors linked to logs, traces, replays and profiles | Grouped into issues by stack trace, message and metadata |
| AI help | Seer agent finds root causes and suggests fixes | AI-powered insights and issue classification |
| Self-hosting | Yes, free, with no guarantees or dedicated support | Not mentioned on the pages I read |
| Breadth | Errors, logs, tracing, replays, profiling, uptime, crons | Infrastructure, APM, logs, security, digital experience and more |
| Track record | Started as an open source project | Named a Leader in Gartner's Magic Quadrant for Observability Platforms, per its site |
Two very different free starts
Both offer a free way in, but they cover different ground. Sentry's free Developer plan is for solo developers on small projects: one user, error monitoring and tracing, email alerts and 10 custom dashboards. Its Team plan opens up unlimited users, integrations and the Seer AI debugging agent, and new users get a run of free session replays for their first three months.
Datadog's free tier sits in infrastructure monitoring: core collection and visualization for up to 5 hosts, with metrics kept for just one day, against 15 months on its paid tiers. Datadog's error tracking page invites you to start there and expand into full observability on one platform, which is exactly how it grows with you.
What Sentry does well
Sentry says it helps developers find and fix what's broken by capturing errors, logs, traces, replays, profiles and metrics and connecting them through distributed tracing. An error links to the logs around it, a trace shows the request's path through every service, and a replay shows what the user saw. Its Seer agent uses all of that context to find the root problem and generate a fix. You can also self-host Sentry for free with Docker and Docker Compose, though its docs are clear there's no dedicated support and you need at least 4 CPU cores and 16 GB of RAM.
What Datadog does well
Datadog's error tracking groups errors into issues automatically using stack traces, messages and runtime metadata, sends real-time alerts for new, recurring and high-volume errors and points to suspect commits. It supports more than ten languages and frameworks. The bigger draw is everything around it: infrastructure monitoring with more than 1,000 integrations on paid tiers, APM, log management, security and digital experience monitoring in one place.
How to choose
- You're a solo developer or small app team: Sentry's free Developer plan is a natural start.
- You need to monitor servers, containers and logs as well as code: Datadog.
- Your data must stay on your own servers: Sentry offers self-hosting.
- You want an AI agent that proposes code fixes: Sentry's Seer is built for that.
- You already use Datadog for infrastructure: try its error tracking before adding another tool.
For more on the developer toolbox, see what to look for in developer productivity tools, and these ChatGPT prompts for faster coding help once you've found the bug.
My advice on Sentry or Datadog
If you build an app and mainly need to know when it breaks and why, start with Sentry; its free plan and Seer agent get you debugging fast. If you run infrastructure as well as code and want one place for metrics, logs, security and errors, Datadog makes more sense, and its free tier lets you try the infrastructure side first. You can also run both, Sentry for developers and Datadog for operations, so don't force a single choice if your teams work differently.
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Frequently asked questions
Is Sentry free?
Sentry's Developer plan is free for one user and includes error monitoring and tracing. Paid plans add unlimited users and more features, and self-hosted Sentry is free to run.
Does Datadog have a free plan?
Datadog's Infrastructure Free tier covers core collection and visualization for up to 5 hosts with 1-day metric retention.
Can I self-host Sentry?
Yes. Sentry's docs explain how to run it on your own server using Docker and Docker Compose, with no guarantees or dedicated support.
Does Datadog do error tracking?
Yes. Datadog Error Tracking groups errors into issues using stack traces, messages and runtime metadata and alerts you to new and recurring errors.
What is Sentry Seer?
Seer is Sentry's AI debugging agent. It uses errors, traces, logs and replays to find the root problem and generate a fix.
