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Alternatives · Memory & Evals

Braintrust alternatives (2026)

Braintrust: The platform for teams whose deployment loop is change-measure-ship.

Its Catch: Eval-first means observability is secondary—if your primary loop is debugging traces, look elsewhere.

Below: 8 free or free-tier tools from the same category (agent memory tools), free and open source first, then the closest match by shared tags. Each keeps its own Catch.

  1. 1.LangfuseOpen-source LLM observability you can self-host

    Free / OSS · Open-Core · 36k GitHub stars

    VerdictThe LLM observability platform for teams who want to own their data.

    CatchLicense: the core is MIT, but anything under the ee/ directories is under a separate enterprise license — check which features you rely on before calling your deployment fully MIT. Self-hosting means self-operating—you are running Postgres, ClickHouse, Redis, and the app. Observability-first means evals are layered on, not central.

  2. 2.PromptfooMIT LLM evals & red-teaming CLI; Community free, 10k probes/mo

    Free / OSS · Freemium · 26.1k GitHub stars

    VerdictMIT eval/red-team CLI. Free core; probe cap + Enterprise sales wall.

    CatchVs DeepEval/Braintrust: YAML/CLI-first, not pytest-native Python or Braintrust SaaS. Community caps red-team probes (~10k/mo); Enterprise/On-Prem are contact-sales (SSO, dashboards, dedicated runner). LLM API costs are yours. Acquisition governance is a multi-year bet.

  3. 3.DeepEvalApache-2.0 pytest-style LLM/agent evals; Confident AI is the paid cloud

    Free / OSS · Apache-2.0 · 18.9k GitHub stars

    VerdictApache-2.0 LLM unit tests. Free locally; Confident AI starts free then $200.

    CatchOSS is the runner — collaboration/dashboards/monitoring are Confident AI (Free: 2 seats/1 project/5 runs/wk; Starter $200/mo; Team $2k/mo). LLM-as-judge burns provider tokens. Vs Ragas: broader agent/chat coverage, not RAG-only.

  4. 4.iFixAiApache-2.0 agents eval/audit — pip install, premium ≠ paywall

    Free / OSS · Apache-2.0 · 29.7k GitHub stars

    VerdictApache agents eval/audit when you want pip-installable scoring without an eval SaaS gate — not Braintrust/Langfuse/Ragas/Promptfoo’s lanes; premium ≠ required.

    CatchVs Braintrust / Langfuse / Ragas / Promptfoo: Braintrust is eval-first commercial; Langfuse is MIT obs/self-host; Ragas is Apache RAG/agent metrics + CI scorers; Promptfoo is OSS prompt/agent eval — iFixAi’s catch is agents eval/audit as an installable audit kit, not Braintrust seats, not Langfuse traces, not Ragas metrics alone, not Promptfoo prompt suites. Stars grow fast (~47 a week): judge the audit loop, not the counter.

  5. 5.Mem0Memory infrastructure for AI agents that actually persists

    Free / OSS · Freemium · 67.4k GitHub stars

    VerdictThe memory layer most agent teams should use instead of building.

    CatchExternal dependency for a core capability. Async processing adds latency. Platform optimizations are not in the open-source SDK. You are trusting Mem0 with potentially sensitive user data.

  6. 6.LettaEpisodic memory for agents that think across sessions

    Free / OSS · Apache-2.0 · 25.2k GitHub stars

    VerdictThe memory architecture for agents that need to think long-term.

    CatchMore complex to reason about than simple vector retrieval. The paging mechanism adds latency and orchestration overhead. Documentation assumes understanding of the original MemGPT paper.

  7. 7.GraphitiApache-2.0 temporal knowledge graphs for agent memory; Zep's OSS engine

    Free / OSS · Apache-2.0 · 32k GitHub stars

    VerdictApache-2.0 temporal memory graphs. Free self-host; Zep Cloud is the paid path.

    CatchFramework only — you run a graph DB + ops. Zep Community Edition deprecated; full Zep SaaS is separate (Free credits then Flex ~$104/mo billed annually). Not a drop-in chat history store. Schema/ops cost vs Mem0 Docker.

  8. 8.agentsviewMIT local-first agent session/cost archive — 20+ coding agents

    Free / OSS · OSS/MIT · 6.2k GitHub stars

    VerdictMIT local agent archive. Session/cost on disk; not Langfuse/Braintrust cloud.

    CatchVs Langfuse / Braintrust (cloud LLM observability): agentsview is a local session/cost archive for coding-agent transcripts, not a hosted tracing/eval platform. Optional anonymous telemetry ping; you still need the agent logs on disk. Not a replacement for production OpenTelemetry of your app’s LLM calls.

FAQ

What are the best free alternatives to Braintrust?
Langfuse, Promptfoo, DeepEval, iFixAi, Mem0. All are reviewed on Stack Gems in the same category (agent memory tools); 8 free or open source.
What is the catch with Braintrust?
Eval-first means observability is secondary—if your primary loop is debugging traces, look elsewhere.
Is there an open-source alternative to Braintrust?
Yes: Langfuse (Open-Core), Promptfoo (Freemium), DeepEval (Apache-2.0), iFixAi (Apache-2.0).

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