What it is
Langfuse records what an LLM application does: each model call, retrieval step and tool call becomes a span in a trace, with inputs, outputs, latency, tokens and cost. On top of that it offers prompt versioning, datasets, experiments, LLM-as-judge scoring, human annotation queues and dashboards. It accepts OpenTelemetry data and has Python and JavaScript SDKs plus integrations with most agent frameworks.
The core is MIT-licensed; code in the ee/ folders is under a commercial licence. The self-hosting pricing page lists tracing, prompt management, evaluations, enterprise SSO and organisation-level RBAC as free. Project-level RBAC, audit logs, data retention policies, SCIM and server-side masking need the custom-priced Enterprise licence.
Langfuse Cloud has a free Hobby plan (50,000 units a month, 30 days of data access, two users), Core at $29 a month, Pro at $199 and Enterprise at $2,499, each with 100,000 units included and overage from $8 per 100,000. ClickHouse, the database Langfuse already ran on, acquired the company in January 2026 and said the licence would not change.
Our review
Langfuse is where a team without a framework allegiance should start on LLM observability, self-hosted or not. It has about 36,200 GitHub stars, released v4.68.0 on 22 October 2026, and its free self-hosted edition is unusually complete: tracing, prompts, evaluations, dashboards and even Okta or Entra SSO carry no licence fee.
The self-hosted versus cloud decision is mostly about data and operations. Prompts and responses often contain customer data, and keeping traces in your own cloud avoids adding a processor to your compliance paperwork. The price is running Postgres, ClickHouse, Redis or Valkey and S3-compatible storage; the docs label Docker Compose as fit for testing only, with no high availability or backups, and point production users to Helm or the AWS, Azure and GCP templates. On the cloud, SOC 2 Type II and ISO 27001 reports and a HIPAA BAA start at Pro, and enterprise SSO costs a further $300 a month there, a feature the free self-hosted build includes.
The ClickHouse acquisition has changed the commercial wrapping rather than the code. Self-hosted Enterprise is now quoted as an addition to a ClickHouse commercial plan and can be billed through AWS Marketplace, while the MIT core and release pace continue. Self-hosted instances send anonymous telemetry by default, which excludes traces and prompts and stops with TELEMETRY_ENABLED=false. Of four published security advisories, the most recent, in April 2026, let ordinary members read stored LLM provider API keys.
LangSmith goes deeper for LangGraph agents and adds agent hosting; Arize Phoenix has the stronger evaluation-research lineage. Langfuse's paid line falls exactly where regulated firms look first: audit logs, retention policies and project-level permissions all sit behind the Enterprise licence.
Where it earns its place
A three-person startup shipping a RAG support bot
See why answers go wrong and what each conversation costs
SDK or OpenTelemetry instrumentation sends every retrieval and model call as a trace. Core cloud at $29 a month includes 100,000 units with 90 days of history; at 1 million units a month the bill is $101 by Langfuse's own worked example.
A platform team at a European insurer
Trace LLM calls without sending customer prompts to a new processor
Deploy the Helm chart in the firm's own cloud and keep traces in its ClickHouse. The free edition covers SSO and evaluations; audit logs and retention policies require a custom-priced Enterprise licence, so budget for that before the security review.
An AI engineer iterating on prompts for a summarisation feature
Version prompts and compare them against a test set before release
Prompt management, datasets and LLM-as-judge scores run in one tool. On the cloud each score is a billable unit, so large automated evaluation runs add to the monthly bill alongside production traces.
Before you commit
- Setup
- docker compose up runs it locally in about five minutes, per the README; production needs Postgres, ClickHouse, Redis or Valkey and S3-compatible storage via Helm or the AWS, Azure or GCP templates.
- Integrations
- Python and JavaScript SDKs, an OpenTelemetry endpoint, and integrations for most agent frameworks and model gateways; prompts can be fetched at runtime from its API.
- Data and privacy
- Self-hosted data stays in your infrastructure; anonymous usage telemetry is on by default and excludes trace content (TELEMETRY_ENABLED=false disables it). Cloud offers US, EU and Japan regions, with SOC 2 Type II, ISO 27001 reports and HIPAA BAA from Pro.
- Cost at scale
- Langfuse's own worked examples: Pro at 5 million units is $551 a month, Pro plus Teams at 25 million is $2,176, and Enterprise at 100 million is $8,801. Self-hosted infrastructure cost is not published and depends on ClickHouse sizing.
- Limits
- 1,109 open issues and pull requests. Cloud history is capped by plan (30 days Hobby, 90 days Core), and Hobby allows only two users.
What's good
- Free self-hosted edition includes SSO, evals and prompt management
- Published per-unit cloud pricing with worked examples
- OpenTelemetry and broad framework support
- Cloud data regions in the US, EU and Japan
What's not
- Production self-hosting means running ClickHouse, Postgres, Redis and object storage
- Audit logs, retention policies and project-level RBAC need Enterprise
- Enterprise SSO on the cloud costs $300/month extra
Best for
Teams that want framework-neutral tracing and evaluation they can self-host for free or buy as a reasonably priced cloud service.
Alternatives
Langfuse: common questions
- Is Langfuse worth it?
- Framework-neutral LLM tracing you can own outright: the free self-hosted build covers nearly everything, and the cloud is priced down to the unit. We rate it 4.6 out of 5.
- How much does Langfuse cost?
- Free and open source under MIT, except ee/ folders under a commercial licence. Cloud: Hobby free (50k units/month); Core $29/month; Pro $199/month (Teams add-on +$300); Enterprise $2,499/month; overage $8 per 100k units, falling to $6 above 50M.
- What are the downsides of Langfuse?
- Production self-hosting means running ClickHouse, Postgres, Redis and object storage; audit logs, retention policies and project-level RBAC need Enterprise; enterprise SSO on the cloud costs $300/month extra.
- Who is Langfuse best for?
- Teams that want framework-neutral tracing and evaluation they can self-host for free or buy as a reasonably priced cloud service.
- How much does Langfuse cost for a team or in production?
- Langfuse's own worked examples: Pro at 5 million units is $551 a month, Pro plus Teams at 25 million is $2,176, and Enterprise at 100 million is $8,801. Self-hosted infrastructure cost is not published and depends on ClickHouse sizing.
- Is Langfuse safe for company data?
- Self-hosted data stays in your infrastructure; anonymous usage telemetry is on by default and excludes trace content (TELEMETRY_ENABLED=false disables it). Cloud offers US, EU and Japan regions, with SOC 2 Type II, ISO 27001 reports and HIPAA BAA from Pro.
- What are the best Langfuse alternatives?
- The closest alternatives we have reviewed are Arize Phoenix, Opik and LiteLLM.
Answers checked Oct 23, 2026.
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