LangSmith pricing
How LangSmith charges, what to know before you commit, and what you'd pay at your usage — next to what the alternatives would cost for the same thing.
How it charges
Checked 2026-10-03 on www.langchain.com ↗ · USD, list pricesIn short
Free for one seat with 5k base traces a month; Plus is $39 per seat per month with 10k traces, then $0.005 per extra base trace.
- Free plan
- Yes
- Cheapest paid plan
- $39/mo
- Side project
- $25/mo Developer
- Growing
- $475/mo Developer
- Scaling
- $24,975/mo Developer
What the model leaves out
Extra base traces (14-day retention) cost 0.005 LSU each at $1 per LSU; upgrading a trace to 180-day extended retention adds 0.0025 LSU. Developer is limited to 1 seat; Plus is $39 per seat per month (one seat modeled) with 10k traces included in total. Deployments, Fleet and sandboxes are metered separately.
Before you commit
- Plus charges per seat, and every user in the organization, including invited users, counts; seats added mid-month are prorated, with no credit for removed seats.
- Base traces are kept only 14 days; extending a trace to 180 days adds 0.0025 LSU ($0.0025) each.
- Deployments, Fleet, Engine, sandboxes and Tuned Evaluators are metered in LSUs on top of seats and traces.
- Traces are billed monthly in arrears.
| Plan | Monthly fee | Traces per month |
|---|---|---|
| Developer | None | 5k traces includedthen $0.005 per trace |
| Plus | $39/mo | 10k traces includedthen $0.005 per trace |
What you'd pay
Developer95k traces × $0.005 per trace$475/moThe same usage elsewhere
Cost as you grow
All LLM observability & evals pricing, compared →Which one fits your situation →