A agentindex
Comparison

Fiddler vs LangSmith

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

Fiddler

AI observability and governance for enterprise.

  • + Strong governance and compliance story
  • + Good for regulated enterprise
  • − Enterprise-priced
  • − Heavier than dev-focused tools

LangSmith

LangChain's observability and eval platform.

  • + Best-in-class when you already use LangChain
  • + Strong tracing UX
  • − Proprietary and cloud-only
  • − Vendor lock-in to LangChain
Spec Fiddler LangSmith
Category eval-observability eval-observability
License Proprietary Proprietary
Open source No No
Self-hostable No No
MCP support No No
Pricing paid freemium
Starting price Custom (enterprise) Free developer tier
Models multi multi
Languages python python, typescript
GitHub stars — —
Last activity — —