// comparison
W&B Weave vs LangSmith: Tracing and Evals
By the TrueIQ editorial team at Ahzy Capital · Prices last verified Oct 28, 2026 · How we test
Weave is Weights & Biases' toolkit for tracing and evaluating LLM apps. LangSmith is LangChain's. Both record traces, run evaluations and manage datasets.
| W&B Weave | LangSmith | |
|---|---|---|
| What it is | Weights & Biases toolkit for tracing, evaluating and iterating on LLM applications. | LangChain's platform for tracing, evaluating and monitoring LLM apps and agents, framework agnostic. |
| Category | Observability | Observability |
| Free tier | Yes ($0/mo) | Yes (1 seat Developer) |
| Entry paid price | Pro from $60/mo | Plus $39/seat/mo + usage |
| Pricing source | Official page | Official page |
| Last verified | Oct 28, 2026 | Oct 28, 2026 |
Pricing
Weave is covered by Weights & Biases' main pricing: a free tier and a Pro plan billed monthly. LangSmith has a free single seat plan and a per seat Plus plan plus usage.
Fit
Teams that already track model training in W&B get one place for training runs and app evaluations with Weave. Teams building on LangChain or LangGraph get the tightest integration with LangSmith.
Verdict
Already on W&B? Use Weave. Building on LangChain? Use LangSmith. Neither? Compare both free tiers on a real trace, and look at open source options like Langfuse.
Prices change often. See the live pricing tracker for the latest checked figures.