Alternatives · Braintrust
Braintrust alternatives
15 platforms that trace and evaluate AI agents, compared with Braintrust 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 Braintrust alternatives?
The best Braintrust alternative depends on why you are moving. Block or hold a live agent action: Prefactor, Galileo and Maxim AI. Open source and self-hosting without an Enterprise plan: Langfuse and Opik. A LangChain-native stack: LangSmith.
| If you need | Look at |
|---|---|
| Block or hold a live agent action | Prefactor scores every production run and can hold, block or stop the action that fails. Galileo and Maxim AI also act during a run; Braintrust scores after the request.Prefactor platformBraintrust vs GalileoBraintrust vs Maxim AI |
| Open source and self-hosting without an Enterprise plan | Langfuse (MIT) or Opik (Apache-2.0). Braintrust's core platform is closed source and self-hosts only its data plane, on Enterprise.Braintrust vs LangfuseBraintrust vs Opik |
| A LangChain-native stack | LangSmith, built by the LangChain team.Braintrust vs LangSmith |
How do the Braintrust alternatives compare?
Braintrust 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 |
|---|---|---|---|---|---|
| Braintrust | Yes | No | Partly | Partly | Replacing |
| Prefactor | Yes | Yes | Partly | Partly | Platform |
| Langfuseownership changed | Yes | No | Yes | Yes | vs Braintrust |
| LangSmith | Yes | Partly | Partly | Yes | vs Braintrust |
| Arizeownership changed | Yes | Partly | Partly | Yes | vs Braintrust |
| Heliconeownership changed | Partly | Partly | Yes | Yes | vs Braintrust |
| Galileoownership changed | Yes | Yes | Partly | Yes | vs Braintrust |
| HoneyHive | Yes | No | Partly | Yes | vs Braintrust |
| Confident AI | Yes | No | Partly | Partly | vs Braintrust |
| Datadog | Yes | Partly | Partly | No | vs Braintrust |
| Fiddler | Yes | Partly | Partly | Yes | vs Braintrust |
| Logfire | Yes | Partly | Partly | Partly | vs Braintrust |
| Opik | Yes | Partly | Yes | Yes | vs Braintrust |
| Raindrop | Yes | No | Partly | Partly | vs Braintrust |
| Maxim AI | Yes | Yes | Partly | Yes | vs Braintrust |
| W&B Weaveownership changed | Yes | Partly | Partly | Yes | vs Braintrust |
How does Prefactor compare with Braintrust?
Where Prefactor goes further
- Prefactor can block or hold a live agent action; Braintrust does not.
Where Braintrust goes further
- Braintrust includes prompt versioning and a playground. Prefactor evaluates how prompts perform in live runs rather than providing a prompt playground or registry.
- Braintrust includes a gateway or proxy in the request path. Prefactor instruments agents through SDKs and OpenTelemetry, so it adds no gateway to the request path.
Common questions about Braintrust alternatives
What are the best Braintrust alternatives?
The best Braintrust alternative depends on why you are moving. Block or hold a live agent action: Prefactor, Galileo and Maxim AI. Open source and self-hosting without an Enterprise plan: Langfuse and Opik. A LangChain-native stack: LangSmith.
Is there an open-source alternative to Braintrust?
As of 20 October 2026, Langfuse (MIT), 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 Braintrust 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. Online scoring, alerts and Patterns judge traces after they are logged. Braintrust does not document blocking, guardrails or approvals on live agent actions.
Who owns Braintrust?
As of 20 October 2026: Braintrust Data, Inc., an independent company that raised an $80M Series B led by ICONIQ in February 2026.
Is Braintrust open source?
Partly. The platform is proprietary. Its SDKs, the Autoevals scoring library and its Terraform deployment modules are open source.
How much does Braintrust cost?
As of 20 October 2026: Starter is free with 1 GB of processed data, 10K scores and 14-day retention. Pro is $249 a month with 5 GB and 50K scores. Every plan includes unlimited users. Enterprise, the only plan with self-hosting, is custom.
Can Braintrust block or hold a live agent action?
No. Online scoring, alerts and Patterns judge traces after they are logged. Braintrust does not document blocking, guardrails or approvals on live agent actions.
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.