Alternatives · Langfuse
Langfuse alternatives
15 platforms that trace and evaluate AI agents, compared with Langfuse on production evals, runtime controls, licence and hosting. Checked against each vendor's own pages on 20 October 2026.
Prefactor is an agent evaluation platform for teams building AI agents: it observes every agent run from development to production, evaluates whether the agent did its job, and shows how to improve it.
TL;DR
What are the best Langfuse alternatives?
The best Langfuse alternative depends on why you are moving. Act on a failing run, not only score it afterwards: Prefactor, Galileo and Maxim AI. Another open-source platform you can self-host: Opik. Tracing, evals and deployment from the LangChain team: LangSmith.
Langfuse status, 20 October 2026: Acquired by ClickHouse; licence and self-hosting unchanged, per Langfuse.
| If you need | Look at |
|---|---|
| Act on a failing run, not only score it afterwards | Prefactor scores every production run and can hold, block or stop a failing action. Galileo (Agent Control) and Maxim AI (Bifrost guardrails, Enterprise) also act during a run.Prefactor platformLangfuse vs GalileoLangfuse vs Maxim AI |
| Another open-source platform you can self-host | Opik, from Comet, is Apache-2.0 and its self-hosted release includes online LLM-as-a-judge rules on production traces.Langfuse vs Opik |
| Tracing, evals and deployment from the LangChain team | LangSmith, which traces LangChain and LangGraph with a single environment variable.Langfuse vs LangSmith |
How do the Langfuse alternatives compare?
Langfuse first for reference, then Prefactor, which publishes this page, then the other 14. "Partly" means limited, for example to model calls, one plan or a preview.
| Platform | Scores production traffic | Acts during a run | Open source | Self-hosting | Compare |
|---|---|---|---|---|---|
| Langfuseownership changed | Yes | No | Yes | Yes | Replacing |
| Prefactor | Yes | Yes | Partly | Partly | Platform |
| LangSmith | Yes | Partly | Partly | Yes | vs Langfuse |
| Arizeownership changed | Yes | Partly | Partly | Yes | vs Langfuse |
| Braintrust | Yes | No | Partly | Partly | vs Langfuse |
| Heliconeownership changed | Partly | Partly | Yes | Yes | vs Langfuse |
| Galileoownership changed | Yes | Yes | Partly | Yes | vs Langfuse |
| HoneyHive | Yes | No | Partly | Yes | vs Langfuse |
| Confident AI | Yes | No | Partly | Partly | vs Langfuse |
| Datadog | Yes | Partly | Partly | No | vs Langfuse |
| Fiddler | Yes | Partly | Partly | Yes | vs Langfuse |
| Logfire | Yes | Partly | Partly | Partly | vs Langfuse |
| Opik | Yes | Partly | Yes | Yes | vs Langfuse |
| Raindrop | Yes | No | Partly | Partly | vs Langfuse |
| Maxim AI | Yes | Yes | Partly | Yes | vs Langfuse |
| W&B Weaveownership changed | Yes | Partly | Partly | Yes | vs Langfuse |
How does Prefactor compare with Langfuse?
Where Prefactor goes further
- Prefactor can block or hold a live agent action; Langfuse does not.
Where Langfuse goes further
- Langfuse includes prompt versioning and a playground. Prefactor evaluates how prompts perform in live runs rather than providing a prompt playground or registry.
- Langfuse can be self-hosted. Prefactor is hosted, with enterprise deployments in the customer's region or environment.
- Langfuse publishes its platform as open source. Prefactor publishes its deterministic agent evals package under Apache-2.0; the platform itself is hosted.
Common questions about Langfuse alternatives
What are the best Langfuse alternatives?
The best Langfuse alternative depends on why you are moving. Act on a failing run, not only score it afterwards: Prefactor, Galileo and Maxim AI. Another open-source platform you can self-host: Opik. Tracing, evals and deployment from the LangChain team: LangSmith.
Is there an open-source alternative to Langfuse?
As of 20 October 2026, Helicone (Apache-2.0, in maintenance mode) and Opik (Apache-2.0) publish their platforms as open source and can be self-hosted. Arize Phoenix is free to self-host but source-available under the Elastic License 2.0. Prefactor publishes its deterministic agent evals package under Apache-2.0; the platform itself is hosted.
Which Langfuse alternatives can block or hold a live agent action?
As of 20 October 2026, Prefactor can hold an action for approval, block it under a runtime policy or stop the run with a kill switch. Galileo and Maxim AI can also act during a run. LangSmith, Arize, Helicone, Datadog, Fiddler, Logfire, Opik and W&B Weave offer partial controls, mostly on model calls or content. The rest evaluate after the fact. No. Langfuse evaluates runs after they happen. Its documentation says run-time protection comes from separate libraries, and Langfuse scores those measures afterwards.
Who owns Langfuse?
As of 20 October 2026: ClickHouse, Inc., which acquired Langfuse in January 2026. Langfuse said its roadmap and licence would not change and that self-hosting stays a first-class option.
Is Langfuse open source?
Yes. The repository is MIT-licensed, apart from add-on features in its ee folders that need a licence key. Self-hosting on Docker or Kubernetes is free.
How much does Langfuse cost?
As of 20 October 2026: Hobby is free with 50k units a month and 30 days of data, and self-hosting is free. Core is $29 a month for 100k units, then $8 per 100k. Pro is $199 a month, and Enterprise is $2,499 a month or custom.
Can Langfuse block or hold a live agent action?
No. Langfuse evaluates runs after they happen. Its documentation says run-time protection comes from separate libraries, and Langfuse scores those measures afterwards.
What is Prefactor?
Prefactor is an agent evaluation platform for teams building AI agents: it observes every agent run from development to production, evaluates whether the agent did its job, and shows how to improve it. As of 20 October 2026, its free tier includes 5,000 spans a month.