“1. Braintrust Best match for your request”
“- Side-by-side experiment comparison.”
“- Row-level diffs showing improved, regressed, and unchanged cases.”
“- Per-example outputs, scores, metadata, cost, and latency.”
“- Filtering and investigation of individual failures.”
“Particularly good for teams iterating on prompts, models, and evaluators.”
“Self-hosting | No | Yes | Yes”
“2. Langfuse Best open-source option”
“- Matched dataset rows with outputs side by side.”
“- Select a baseline and candidate experiment.”
“- Green/red score, cost, and latency differences.”
“- Drill into individual traces and annotate failures.”
“- Self-hosting available.”
“Its October 2026 updates also added improved metric charts and regression filtering.”
“- Compare multiple prompts and models.”
“- Interactive table of test cases and outputs.”
“- Side-by-side response comparison.”
“- Filter failures and export results to HTML, JSON, and CSV.”
“- Particularly useful for CI/CD regression testing.”
“Self-hosting | No | Yes | Yes”
“Trace investigation | Yes | Yes | Limited”
“Human review | Yes | Yes | More limited”
“- Dataset-based experiments.”
“- Evaluation and regression analysis.”
“- Human annotation and pairwise review.”
“- Detailed tracing for investigating why individual examples failed.”
“Particularly interesting if you're building with LangChain or LangGraph.”