Langfuse vs Helicone vs Braintrust: LLM Observability Compared (2026)
Langfuse, Helicone, and Braintrust help you trace, monitor, and evaluate LLM apps — but they emphasize different parts of the LLMOps loop.
Langfuse vs Helicone vs Braintrust: LLM Observability Compared (2026)
Once an LLM feature is live, you need to see what it's doing and whether quality is holding. Langfuse, Helicone, and Braintrust each cover part of that loop — tracing, monitoring, and evaluation — with different emphases.
Quick verdict
- Langfuse — the popular open-source all-rounder for tracing plus evals; a strong default.
- Helicone — the fastest way to add logging and a proxy gateway, though check its current maintenance status first.
- Braintrust — the deepest evaluation and prompt-iteration workflow for teams shipping quickly.
Tracing and monitoring
Helicone is the quickest to adopt: route requests through its proxy (or SDK) and you immediately get logs, cost, and latency with minimal code. Langfuse offers rich, structured tracing of multi-step chains and agents, which pays off as your app grows more complex. Braintrust captures traces too, but its center of gravity is evaluation rather than raw monitoring.
Evaluation
This is where the tools diverge most. Braintrust is built around the eval loop — scoring outputs, comparing prompt versions, and catching regressions before they ship — which suits teams iterating fast on quality. Langfuse includes solid evaluation features alongside its tracing, giving you one tool for both. Helicone is lighter on structured evals and heavier on observability and gateway features.
Open source and hosting
Langfuse is open-source with a generous cloud tier and self-hosting, which many teams value for data control. Helicone also offers an open-source, self-hostable core. Braintrust is primarily a managed product. If self-hosting is a requirement, Langfuse or Helicone are the natural picks.
Which should you pick?
Start with Langfuse if you want one open-source tool for both tracing and evals. Choose Helicone for the fastest drop-in logging and gateway (weighing its post-acquisition status). Choose Braintrust if rigorous, fast evaluation is your priority. See the full best LLM observability tools list for more options, and note you can run more than one — many teams pair a tracer with a dedicated eval tool.
Features and pricing as of August 2026; verify current details with each vendor.