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LangSmith vs Vellum

A side-by-side comparison of LangSmith and Vellum, drawn from Ignaite's continuously-verified listings.

Compared from listings verified as of

LangSmith

Observability

LangChain's hosted observability + eval platform.

View LangSmith

Vellum

Eval

Build, evaluate, and deploy production LLM apps and agents.

View Vellum

At a glance

Feature comparison of LangSmith and Vellum
AttributeLangSmithVellum
Category (differs)ObservabilityEval
PricingFREEMIUMFREEMIUM
LicenseProprietaryProprietary
DeploymentCloudCloud
Platforms (differs)API, WebWeb, API
Model support (differs)Model-agnosticMulti-model
Vendor (differs)LangChainVellum

The honest brief

LangSmith

Deepest native LangChain/LangGraph tracing — but cloud-only, where Langfuse lets you self-host the same.

  • Native LangChain/LangGraph tracing
  • Works standalone via SDKs
  • Datasets + eval orchestration
  • Prompt playground built in
  • Closed source, cloud-only
  • Self-host is Enterprise-only
  • Best value inside LangChain stack

Vellum

Passes model token costs straight through at cost, so the platform fee is unbundled from usage — unlike marked-up LLMOps tools.

  • Visual builder plus Python SDK
  • Prompt, RAG, eval, monitoring in one
  • Eval and test suites before/after deploy
  • Non-technical collaborators supported
  • Free tier available
  • Cloud-only platform
  • Breadth over best-in-class depth
  • Seat costs at Pro/Enterprise
  • Lock-in to its workflow model