Best AI Evals

ComparisonChecked Nov 8, 2026

Langfuse vs LangSmith

Both combine tracing, prompt tooling, and online and offline evaluation for LLM apps and agents. The main differences are licensing, self-hosting terms, and the pricing unit.

What differs

  • License and self-hosting: Langfuse’s core is MIT-licensed and can be self-hosted for free; self-hosted LangSmith is an add-on to the LangSmith Enterprise plan.
  • Pricing unit: Langfuse Cloud prices by units (Hobby free with 50k units/month; Core $29/month and Pro $199/month with 100k units, then $8 per 100k). LangSmith prices by seat plus traces (Developer $0/seat with 5k base traces; Plus $39/seat with 10k base traces, then pay-as-you-go).
  • Published security: Langfuse lists SOC 2 Type II, ISO 27001, a HIPAA-ready region, and GDPR; LangSmith states SOC 2 Type 2, HIPAA compliance, and GDPR.
  • Ownership: ClickHouse acquired Langfuse (announced January 16, 2026); LangSmith is built by LangChain, Inc.

Who each tends to fit

Teams that must self-host without an enterprise contract may look first at Langfuse. Teams building on LangChain or LangGraph may look first at LangSmith. Trial both on the same traces.

Last checked: . No winner declared.

Side by side

FactLangfuseLangSmith (LangChain)
StatusActive. ClickHouse acquired Langfuse (announced January 16, 2026) and owns 100% of it; Langfuse Cloud keeps running and the core stays MIT-licensed and self-hostable.Active, privately held.
OwnershipSubsidiaryPrivately held
Buying modelHosted SaaS, Open-source or source-available core, Self-hosted, VPC, or on-premHosted SaaS, Self-hosted, VPC, or on-prem
CategoriesOpen-source core (MIT); Hosted SaaS platform (Langfuse Cloud); Self-hosted (free OSS or Enterprise)Hosted SaaS platform; Self-hosted or BYOC deployment (Enterprise add-on)
PricingHobby: free (50k units/month). Core: $29/month (100k units/month, then $8 per 100k units). Pro: $199/month (100k units/month, then $8 per 100k units). Enterprise: $2,499/month. Optional Teams add-on: $300/month. Self-hosted open source: free (MIT); self-hosted Enterprise: custom pricing.Developer: $0/seat per month, 1 seat, up to 5k base traces/month, then pay-as-you-go. Plus: $39/seat per month, up to 10k base traces/month, then pay-as-you-go. Enterprise: custom pricing, with self-hosted and hybrid deployment options.
CertificationsSOC 2 Type II; ISO 27001; HIPAA (HIPAA-ready region); GDPRSOC 2 Type 2; HIPAA compliant; GDPR
LimitationsCode in the repository ee/ directories is under a separate license; core features are MIT (per the repository LICENSE); Ownership changed in January 2026; review contracting entity in diligencePay-as-you-go trace rates beyond the included base traces were not shown in the fetched page text; check the pricing calculator; Self-hosted LangSmith is an add-on to the Enterprise plan
How to buylangfuse.comlangchain.com
Sources[1] [2] [3] [4] [5] [6] Checked 2026-11-08[1] [2] [3] [4] Checked 2026-11-08

Facts come from each vendor’s profile sources. Run a paid pilot before choosing.