Langtrace vs Sentry
Both are observability & tracing tools. Here is how they actually differ on price, billing model and deployment.
Langtrace
An OpenTelemetry-native open-source tracing tool from Scale3 Labs. The cloud is still free because it has never been monetised - which is either a bargain or a runway risk depending on how you read a seed round raised around 2022. The AGPL-3.0 server license is the other thing to check before you commit.
Sentry
Excellent error tracking that keeps appearing in LLM observability roundups where it does not belong. Its AI product, Seer, is a code-debugging agent billed per contributor - not an LLM tracing or evaluation platform.
| Langtrace | Sentry | |
|---|---|---|
| Category | Observability & Tracing | Observability & Tracing |
| Our rating | 3/5 | 2/5 |
| Starting price | Free (not yet monetised) | $26/mo |
| Billing meter | No usage metering | event |
| Free plan | Yes | Yes |
| Free self-hosting | Yes, free | No or paid tier only |
| Best for | Teams that want OpenTelemetry-native tracing with strong vector database visibility, are comfortable with AGPL on the server, and can tolerate the possibility of a pricing model appearing later. | Error tracking and front-end debugging, which it does superbly. It is not the right tool for observing or evaluating LLM applications, and should be paired with one rather than substituted for one. |
Our verdict on Langtrace
Langtrace is a well-built OpenTelemetry-native tracing tool with unusually good vector database instrumentation, and right now it costs nothing. Two things stop us rating it higher, and neither is about the product quality. The first is the license - the application is AGPL-3.0 while the SDKs are Apache 2.0, and that split matters. Instrumenting your app is safe; modifying the server and offering it as a service brings copyleft obligations most commercial teams will want legal review on. The second is commercial. The vendor states it is not currently charging for the cloud and will announce when it decides to monetise, and public funding data shows a roughly $5.3M seed raised around 2022. A free cloud with no revenue model and a four-year-old seed round is not a stable planning assumption. Use it, and self-host if it becomes load-bearing.
Full Langtrace review →Our verdict on Sentry
We are including Sentry because it keeps appearing in LLM observability comparisons, and the most useful thing we can tell you is that it does not belong in them. Sentry is an outstanding error tracking and performance monitoring product. What it is not is an LLM observability platform. It does not do prompt and completion capture, token accounting, per-model cost attribution or output-quality evaluation in the way this category means those terms. The confusion comes from Seer, Sentry's AI product, which roundups see and file as AI observability. Seer is a code debugging agent - it looks at your errors and proposes fixes - billed at $40 per active contributor per month, where an active contributor is anyone opening two or more pull requests to a Seer-enabled repository in a billing cycle. That is a developer productivity tool, not agent observability. Run Sentry for your application errors, absolutely. Run something else for your LLM calls.
Full Sentry review →Frequently Asked Questions
What is the main difference between Langtrace and Sentry?
Langtrace: Teams that want OpenTelemetry-native tracing with strong vector database visibility, are comfortable with AGPL on the server, and can tolerate the possibility of a pricing model appearing later. Sentry: Error tracking and front-end debugging, which it does superbly. It is not the right tool for observing or evaluating LLM applications, and should be paired with one rather than substituted for one. Both sit in Observability & Tracing, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, Langtrace or Sentry?
It depends entirely on your workload shape, because they meter differently - Langtrace bills on no usage metering and Sentry bills on event. Published starting prices are Free (not yet monetised) and $26/mo respectively, but those numbers are not comparable until you apply them to the same traffic. Use our cost calculator to model both against your own request volume and span count.
Can I self-host Langtrace or Sentry?
Langtrace: Yes, free. Sentry: No or paid tier only. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.