Head-to-head
Langfuse vs LangSmith: which one in 2026?
Langfuse is an LLM observability and prompt management platform with MIT-licensed features that can be self-hosted, and LangSmith is the tracing, evaluation and deployment product from LangChain, Inc. The practical split is seats versus units: LangSmith charges per seat, Langfuse charges by usage units with unlimited users from its Core plan.
Verdict
Langfuse is the stronger default for most teams because the price does not rise with headcount, the self-hosting and EU region options are documented, and its audits are named on a page we could open. LangSmith earns its place when the stack is already LangChain or LangGraph and the team wants trace insights and deployments under one login. Langfuse's team joined ClickHouse in January 2026, so check its roadmap statements, and ask LangChain for its security documents.
Langfuse and LangSmith side by side
| Langfuse | LangSmith | |
|---|---|---|
| Price entry | $29 per month (Core) | $39 per seat per month (Plus) |
| Billing unit | Usage units: Hobby includes 50k a month, Core 100k, then $8 per 100k, falling to $6 per 100k from 50 million units. | Seats plus traces: Developer is one seat with 5k base traces, Plus is $39 per seat with 10k base traces, then pay as you go. |
| Cost for a team | Core costs $29 per month with unlimited users, and Pro is $199 per month, so adding colleagues does not change the price. | Plus lists $39 per seat per month with unlimited seats, so the bill grows with the number of people using it. |
| How long traces stay | Data access is 30 days on Hobby, 90 days on Core and 3 years on Pro, with retention management on Pro. | Base traces are kept for 14 days and extended traces for 180 days; upgrading a trace from base to extended costs an extra fee. |
| Self-hosting | Docker Compose, Helm and Terraform paths are documented, and self-hosters can choose any region or provider. | Self-hosted and hybrid deployment sit on Enterprise, and the SmithDB trace database can run inside your own VPC. |
| Cloud regions | Cloud regions are US (Oregon), EU (Ireland) and Japan, chosen at sign-up, mainly on AWS and ClickHouse Cloud. | The product page states hosted deployments store data in GCP us-central-1; no EU or other region is listed on the pages checked. |
| Evaluation and prompts | LLM-as-a-judge, heuristic functions and human review, plus datasets, experiments, a prompt playground and one-click prompt rollbacks. | Online LLM-as-judge and code evals, trace clustering into failure modes, and alerts by webhook or PagerDuty; prompt tooling is not detailed on the page. |
| Framework fit | Lists LangChain, Vercel AI SDK, LiteLLM, CrewAI, Pydantic AI and LiveKit, with OpenTelemetry for Go, Java, .NET, Ruby, PHP and Swift. | Native tracing for LangChain and LangGraph, plus OpenAI, Anthropic, Vercel AI SDK and LlamaIndex, with OpenTelemetry in both directions. |
| Certifications | The security page names SOC 2 Type II and ISO 27001 audits, with the reports and a HIPAA BAA on the Pro plan. | No certification is stated on the pages opened; the trust and security URLs tried returned 404, so confirm directly with the vendor. |
Where each one wins
Langfuse wins on
- Unlimited users from the $29 Core plan, so a growing team does not raise the base price
- Self-hosting is documented with three deployment tools, and the cloud offers an EU region in Ireland
- SOC 2 Type II and ISO 27001 are named on its security page
LangSmith wins on
- Native fit with LangChain and LangGraph, made by the same company as those frameworks
- Insights groups traces into topics and failure modes, with executive summaries and error-analysis templates
- Deployment and agent Fleet features sit in the same product as tracing, with a free small serverless deployment on Plus
Which to pick
Pick Langfuse if
You want to self-host or keep data in an EU region, have a team of more than a few people, and prefer usage-based pricing.
Pick LangSmith if
Your agents are built on LangChain or LangGraph and you value trace clustering and deployment tooling in the same product, at a per-seat price.
Each tool in context: Langfuse profile, LangSmith profile, and the full Best LLM Observability Tools in 2026.
Frequently asked questions
Does Langfuse cost less than LangSmith for a team of ten?
As of November 2026, Langfuse Core is $29 per month with unlimited users plus usage above 100k units. LangSmith Plus is $39 per seat per month, so ten people is $390 before extra traces. Trace volume differs between the two units, so estimate your monthly usage in each before treating this as a final comparison.
Can I keep LLM traces in the EU with either tool?
Langfuse Cloud offers an EU region in Ireland (eu-west-1), and self-hosting lets you choose any region. LangSmith's product page states hosted deployments store data in GCP us-central-1, and the pages checked list no EU region. Its self-hosted option is part of the Enterprise plan.
Is Langfuse still independent after joining ClickHouse?
The Langfuse about page says the team has been part of ClickHouse since January 2026. It does not use the word acquisition or announce a rename, and the product, pricing page and MIT-licensed features remain online. The legal entity behind Langfuse was not stated on the pages we opened.
How long can I look back at old traces in LangSmith and Langfuse?
LangSmith keeps base traces for 14 days and extended traces for 180 days, with an extra fee to extend. Langfuse gives 30 days of data access on Hobby, 90 days on Core and 3 years on Pro. Choose by how far back your debugging and audit needs reach.