Comparison · LangSmith vs Langfuse
LangSmith vs Langfuse: which one fits your team?
Both trace LLM apps, run evaluations and accept OpenTelemetry. The real differences are licence, hosting, ecosystem and price. This comparison sticks to what each vendor documents.
Last reviewed by the Perimattic AI Suite team
In short
What is the difference between LangSmith and Langfuse?
LangSmith is LangChain’s commercial tracing and evaluation platform, with automatic tracing for LangChain and LangGraph and OpenTelemetry support for everything else; self-hosting is an Enterprise option. Langfuse has an MIT-licensed open-source core you can self-host for free, plus a managed cloud with US, EU, Japan and HIPAA regions. Both offer evaluations, datasets and prompt tooling.
Comparison
LangSmith and Langfuse side by side
Every cell comes from the vendor’s own documentation or pricing page. Plans change, so check the sources before you decide.
| Dimension | LangSmith | Langfuse |
|---|---|---|
| Made by | LangChain | Langfuse |
| Licence | Commercial | MIT core; enterprise features under a commercial licence |
| Self-hosting | Self-hosted and hybrid options on the Enterprise plan | Free self-hosting of the open-source core; enterprise self-hosting is paid |
| Managed cloud | Yes | Yes, with US, EU, Japan and HIPAA regions |
| OpenTelemetry | Standard OpenTelemetry clients for non-LangChain apps | OTLP over HTTP from any OpenTelemetry SDK |
| LangChain integration | Native, automatic tracing for LangChain and LangGraph | Supported through integrations and OpenTelemetry |
| Security attestations | SOC 2 Type II; HIPAA and GDPR stated | SOC 2 Type II and ISO 27001; GDPR; HIPAA region |
| Free plan | Developer: 1 seat, 5k base traces a month | Hobby: 50k units a month, 2 users |
| First paid plan | Plus: $39 per seat per month, 10k base traces included | Core: $29 per month, 100k units included |
| Usage billing | Per trace above the allowance; base and extended retention priced differently | Per 100k units (traces, observations and scores), from $8 and falling with volume |
| Retention | Base traces 14 days; extended traces 180 days | 30 days on Hobby, 90 days on Core, 3 years on Pro and Enterprise |
Vendor details last verified on 1 October 2026.
Which one fits your team
- Choose LangSmith if most of your agents run on LangChain or LangGraph, and you value automatic tracing and tight evaluation loops over self-hosting.
- Choose Langfuse if you want to self-host without a licence fee, need EU or HIPAA cloud regions, or prefer usage-based pricing without per-seat fees.
- Consider Perimattic AI Suite if a compliance team needs traces turned into evidence mapped to HIPAA, SOC 2, the EU AI Act or DORA.
Cost
How the pricing models differ
LangSmith charges per seat and per trace. Langfuse charges a plan fee and per unit, where a trace, each observation inside it and each score all count. A trace with many spans therefore costs more units in Langfuse than a simple one, while LangSmith’s cost grows with team size. Run your own numbers with the LLM observability cost calculator rather than relying on a headline price.
FAQ
Common questions
Short answers to the questions teams ask when they compare these tools.
Is Langfuse a free alternative to LangSmith?
The Langfuse core is open source under the MIT licence and free to self-host, so it can be. You still pay for the infrastructure and the time to run it, and some enterprise features are licensed separately.
Can LangSmith trace apps that don’t use LangChain?
Yes. LangChain documents tracing non-LangChain applications with a standard OpenTelemetry client. Its automatic tracing is strongest for LangChain and LangGraph.
Which is better for regulated industries?
Both publish SOC 2 Type II attestations, and Langfuse offers a HIPAA cloud region. Neither markets evidence exports mapped to regulations such as the EU AI Act or DORA, which is the gap Perimattic AI Suite focuses on.
Can I switch between them later?
More easily if you instrument with OpenTelemetry. Both accept OTLP, so changing backends, or sending to both during a trial, is mostly collector configuration rather than code changes.
Go further
Related tools, guides and services
- Free toolLLM observability cost calculatorCompare LangSmith, Langfuse and Datadog costs for your own trace volume and team size.Open
- Free toolSelf-host vs SaaS cost calculatorEstimate what self-hosting Langfuse would cost you in infrastructure and time.Open
- ArticleHow to evaluate an LLM before deploymentEvaluation practices that work with either tool.Open
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