OpenLIT vs SigNoz
Both are observability & tracing tools. Here is how they actually differ on price, billing model and deployment.
OpenLIT
Apache-2.0 OpenTelemetry-native platform covering LLM tracing, evals, prompts, guardrails and a Vault - plus the one thing nearly every competitor ignores entirely, GPU monitoring for self-hosted inference.
SigNoz
An open-source Datadog alternative that handles LLM telemetry as part of full-stack observability rather than as a separate product. Free to license, but you are running ClickHouse - the cost is infrastructure and ops, not fees.
| OpenLIT | SigNoz | |
|---|---|---|
| Category | Observability & Tracing | Observability & Tracing |
| Our rating | 4/5 | 4/5 |
| Starting price | $0 (Apache 2.0) | $19/mo (startup) or $49/mo |
| Billing meter | No usage metering | gb-ingested |
| Free plan | Yes | Yes |
| Free self-hosting | Yes, free | Yes, free |
| Best for | Teams running self-hosted inference on their own GPUs, where correlating GPU health with model performance matters. Also a strong free choice for anyone wanting broad AI engineering tooling in one Apache-2.0 package. | Teams that want one observability backend for their whole stack rather than a separate LLM tool, are cost-sensitive relative to Datadog, and either have ClickHouse operational capacity or will pay for cloud. |
Our verdict on OpenLIT
OpenLIT is the only tool in this category that takes the GPU layer seriously, and if you run your own inference that alone may decide it. Its OpenTelemetry GPU collector exports utilisation, memory, temperature and power as standard OTel signals, so you can correlate a latency regression with thermal throttling or a KV cache leak in the same dashboard - a class of problem that is completely invisible to Langfuse, LangSmith or Braintrust, because they assume you call an API. Beyond that it is unusually broad for a free tool - Apache 2.0 across the core, covering observability, evals, guardrails, prompt management, a Vault and a Playground. The trade-off is breadth over depth, since each module is lighter than a dedicated competitor, and the community is small at roughly 2,500 stars. Two things we could not resolve - an enterprise eBPF controller is referenced without clear licensing terms, and the project has recently described itself as a Harness Engineering platform without public explanation of what that means.
Full OpenLIT review →Our verdict on SigNoz
SigNoz is the right answer to a question many teams are actually asking - not "which LLM observability tool" but "how do I see my LLM calls alongside everything else without paying Datadog prices." It handles LLM telemetry as one workload within full-stack observability, giving token-level tracing, per-model cost attribution and prompt latency breakdown, all correlated with the databases and microservices underneath. It is genuinely open source and self-hostable with no feature gating. Two honest caveats. Self-hosted free covers the license and nothing else - you are operating ClickHouse, which is resource-hungry, and you inherit the on-call burden of your own monitoring stack going down. And there is no evaluation capability whatsoever, so if you need LLM-as-judge scoring, datasets or regression testing, SigNoz is half your stack and you will pair it with something like DeepEval or promptfoo.
Full SigNoz review →Frequently Asked Questions
What is the main difference between OpenLIT and SigNoz?
OpenLIT: Teams running self-hosted inference on their own GPUs, where correlating GPU health with model performance matters. Also a strong free choice for anyone wanting broad AI engineering tooling in one Apache-2.0 package. SigNoz: Teams that want one observability backend for their whole stack rather than a separate LLM tool, are cost-sensitive relative to Datadog, and either have ClickHouse operational capacity or will pay for cloud. Both sit in Observability & Tracing, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, OpenLIT or SigNoz?
It depends entirely on your workload shape, because they meter differently - OpenLIT bills on no usage metering and SigNoz bills on gb-ingested. Published starting prices are $0 (Apache 2.0) and $19/mo (startup) or $49/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 OpenLIT or SigNoz?
OpenLIT: Yes, free. SigNoz: Yes, free. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.