Langfuse
Open-source LLM observability, prompt management, and evals.
What is Langfuse?
Langfuse is an open-source LLM engineering platform for tracing, prompt management, and evaluation, built on OpenTelemetry to avoid vendor lock-in. Teams use it to debug multi-turn conversations as sessions, version prompts without code changes, run LLM-as-judge or human evaluations, and experiment systematically against datasets. SDKs cover Python and JavaScript with 50+ framework integrations, and the entire stack can be self-hosted via Docker Compose or Kubernetes for free.
Knowledge bases, internal search, operations, data, finance, HR, and back-office tools with AI workflows.
See the full Knowledge & Ops guide to compare more tools, buyer criteria, and related workflows.
Use cases to evaluate
Self-hosting full LLM trace data in your own VPC to satisfy compliance
Versioning and deploying production prompts via labels without redeploying code
Running LLM-as-a-judge scoring against a curated dataset to gate releases
Comparing model providers (OpenAI vs Anthropic vs open-source) on identical traces
Fit to evaluate
Open-source-friendly engineering teams who want to self-host
Startups budget-constrained but needing real observability
Compliance-bound enterprises (healthcare, finance, EU) needing data residency
Multi-provider LLM teams avoiding vendor lock-in via OTel
Business fit
Right for you if you want full ownership of your LLM trace data (self-host for free), you value OpenTelemetry compatibility, and you want prompt versioning, datasets, and evals in one tool. It suits teams building production LLM apps in Python or JS who want to swap models freely without changing instrumentation. Skip if you want a fully managed enterprise platform with deep deployment/Fleet tooling (LangSmith goes further there), or if you have no engineering capacity to operate a self-hosted stack and the Cloud tier limits don't fit.
How to evaluate Langfuse
Use this category when operational data, policies, tasks, or internal requests are spread across disconnected systems.
Confirm the exact workflow
Map Langfuse to one concrete workflow first, such as self-hosting full llm trace data in your own vpc to satisfy compliance. Avoid buying before the owner, trigger, output, and success metric are clear.
Check category fit
Compare internal search, permissions, workflow support, and reporting.
Compare practical alternatives
Shortlist Langfuse against Glean, Guru, Slite so the decision is based on fit, effort, and workflow ownership rather than brand recognition alone.
Validate cost and rollout effort
Cloud: Hobby free (50k units/month, 30 days retention, 2 users). Core $29/month (100k units, 90 days retention, unlimited users). Pro $199/month (3 years retention; +$300/month Teams add-on for SSO/RBAC/Slack support). Enterprise $2,499/month (audit logs, dedicated support engineer). Overage: $8/100k units (1M tier) down to $6/100k (50M+ tier). Self-hosted is free and open source. Also confirm implementation time, support needs, and whether the medium setup matches your team.
Compare Langfuse with alternatives
Use this quick comparison before booking demos or moving data into a new system.
| Primary workflow | Self-hosting full LLM trace data in your own VPC to satisfy compliance, Versioning and deploying production prompts via labels without redeploying code |
|---|---|
| Best-fit team | Open-source-friendly engineering teams who want to self-host, Startups budget-constrained but needing real observability |
| Implementation effort | Medium setup and maintenance profile |
| Pricing check | Free plan + paid plans |
| Closest alternatives | GleanGuruSliteSlab |
Langfuse pricing
| Model | Free plan + paid plans |
|---|---|
| Snapshot | Cloud: Hobby free (50k units/month, 30 days retention, 2 users). Core $29/month (100k units, 90 days retention, unlimited users). Pro $199/month (3 years retention; +$300/month Teams add-on for SSO/RBAC/Slack support). Enterprise $2,499/month (audit logs, dedicated support engineer). Overage: $8/100k units (1M tier) down to $6/100k (50M+ tier). Self-hosted is free and open source. |
| Checked |
Common questions about Langfuse
What is Langfuse?
Langfuse is an open-source LLM engineering platform for tracing, prompt management, and evaluation, built on OpenTelemetry to avoid vendor lock-in. Teams use it to debug multi-turn conversations as sessions, version prompts without code changes, run LLM-as-judge or human evaluations, and experiment systematically against datasets. SDKs cover Python and JavaScript with 50+ framework integrations, and the entire stack can be self-hosted via Docker Compose or Kubernetes for free.
What is Langfuse used for?
Common use cases: Self-hosting full LLM trace data in your own VPC to satisfy compliance; Versioning and deploying production prompts via labels without redeploying code; Running LLM-as-a-judge scoring against a curated dataset to gate releases; Comparing model providers (OpenAI vs Anthropic vs open-source) on identical traces.
How much does Langfuse cost?
Cloud: Hobby free (50k units/month, 30 days retention, 2 users). Core $29/month (100k units, 90 days retention, unlimited users). Pro $199/month (3 years retention; +$300/month Teams add-on for SSO/RBAC/Slack support). Enterprise $2,499/month (audit logs, dedicated support engineer). Overage: $8/100k units (1M tier) down to $6/100k (50M+ tier). Self-hosted is free and open source.
Who is Langfuse best for?
Langfuse fits Open-source-friendly engineering teams who want to self-host, Startups budget-constrained but needing real observability, Compliance-bound enterprises (healthcare, finance, EU) needing data residency, Multi-provider LLM teams avoiding vendor lock-in via OTel. Right for you if you want full ownership of your LLM trace data (self-host for free), you value OpenTelemetry compatibility, and you want prompt versioning, datasets, and evals in one tool. It suits teams building production LLM apps in Python or JS who want to swap models freely without changing instrumentation. Skip if you want a fully managed enterprise platform with deep deployment/Fleet tooling (LangSmith goes further there), or if you have no engineering capacity to operate a self-hosted stack and the Cloud tier limits don't fit.
What are alternatives to Langfuse?
Common alternatives to Langfuse include Glean, Guru, Slite, Slab, Tettra, Sana.