LangSmith vs Langtrace
Both are observability & tracing tools. Here is how they actually differ on price, billing model and deployment.
LangSmith
LangChain's proprietary observability and eval platform. Turnkey and deeply integrated with LangChain and LangGraph - but closed-source, and the trace bill explodes at production scale.
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.
| LangSmith | Langtrace | |
|---|---|---|
| Category | Observability & Tracing | Observability & Tracing |
| Our rating | 3/5 | 3/5 |
| Starting price | $39/seat/mo | Free (not yet monetised) |
| Billing meter | seat | No usage metering |
| Free plan | Yes | Yes |
| Free self-hosting | No or paid tier only | Yes, free |
| Best for | Teams already all-in on LangChain and LangGraph who want the tightest-integrated observability and don't mind the bill | 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. |
Our verdict on LangSmith
The most turnkey observability platform if you already live in LangChain and LangGraph - the tracing is zero-config and the eval tooling is genuinely good. But it's closed source, self-hosting is Enterprise-only, and the trace bill is roughly 25x Langfuse at scale. It's great until you scale or want out, and you can't self-host your way around either problem.
Full LangSmith review →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 →Frequently Asked Questions
What is the main difference between LangSmith and Langtrace?
LangSmith: Teams already all-in on LangChain and LangGraph who want the tightest-integrated observability and don't mind the bill 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. Both sit in Observability & Tracing, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, LangSmith or Langtrace?
It depends entirely on your workload shape, because they meter differently - LangSmith bills on seat and Langtrace bills on no usage metering. Published starting prices are $39/seat/mo and Free (not yet monetised) 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 LangSmith or Langtrace?
LangSmith: No or paid tier only. Langtrace: Yes, free. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.