A agentindex
Comparison

Langfuse vs Weights and Biases Weave

A like-for-like, spec-level comparison. Both entries are verified against their docs and repo.

Langfuse

The most-used open-source LLM observability tool.

  • + Open source and self-hostable
  • + Framework-agnostic via OpenTelemetry
  • − Self-hosting ClickHouse is operational work
  • − Eval features trail dedicated eval tools

Weights and Biases Weave

LLM tracing and eval inside W&B.

  • + Integrates with existing W&B experiment tracking
  • + Good for ML teams already on W&B
  • − Most useful only if you already use W&B
  • − Proprietary
Spec Langfuse Weights and Biases Weave
Category eval-observability eval-observability
License MIT Proprietary
Open source Yes No
Self-hostable Yes No
MCP support No No
Pricing freemium freemium
Starting price Self-host free; cloud tier Free tier
Models multi multi
Languages python, typescript python, typescript
GitHub stars 29.8k —
Last activity 2026-06-25 —