Langfuse
Langfuse is an open-source platform for tracing, evaluating and managing prompts in applications built on language models.
▸ WHAT IT DOES
Langfuse records what an application sends to and receives from language models as traces, so a team can look at what an individual request did. Alongside tracing it has prompt management, evaluation and metrics.
It is offered as a hosted service in four separate regions and as a self-hosted deployment. The self-hosted version runs as two application containers, web and worker, and needs PostgreSQL, ClickHouse, Redis or Valkey, and S3-compatible blob storage.
ClickHouse has acquired Langfuse. The announcement says Langfuse stays open source and self-hostable, with no planned change to its licensing, and that the cloud service keeps running as it is.
▸ OWNER, LICENSE AND HOSTING
| Fact | Value | Source and date checked |
|---|---|---|
| Owner | ClickHouse, which has acquired Langfuse. | SOURCE ↗ 09 OCT 2026 |
| License | MIT for the core. The ee/ directories are under a separate enterprise license. | SOURCE ↗ 09 OCT 2026 |
| Self-hosting | Yes. Docker Compose for testing; Kubernetes (Helm), AWS, Azure and GCP for production. | SOURCE ↗ 09 OCT 2026 |
| Hosted regions | EU (Ireland), US (Oregon), Japan (Tokyo), and a HIPAA region in the US (Oregon). | SOURCE ↗ 09 OCT 2026 |
Each value was read from the vendor's own page on the date shown. How listings are checked
▸ PLANS AND PRICES
| Plan | Price | Included usage | Beyond that | Data retention | Users |
|---|---|---|---|---|---|
| Hobby | Free | 50,000 units a month | – | 30 days of data access | 2 |
| Core | $29 a month | 100,000 units a month | $8 per 100,000 units, lower with volume | 90 days of data access | Unlimited |
| Pro | $199 a month | 100,000 units a month | $8 per 100,000 units, lower with volume | 3 years of data access | Unlimited |
| Enterprise | $2,499 a month | 100,000 units a month | $8 per 100,000 units, lower with volume | 3 years of data access | Unlimited |
A unit is any tracing data point sent to Langfuse: a trace, an observation (a span, event or generation) or a score. Usage beyond the included units is graduated: $8 per 100,000 units up to 1 million, $7 up to 10 million, $6.50 up to 50 million and $6 above that. The page lists discounts for early-stage startups, research and students, non-profits and open-source projects. Self-hosting the open-source version carries no license fee.
As stated on the vendor's pricing page on 09 OCT 2026. A dash means the page does not say.
▸ PRICING HISTORY
The pricing page has been checked daily since 10 OCT 2026. No price change has been recorded since then.
▸ WHERE IT FITS
Teams that want tracing they can run on their own infrastructure, or that need trace data kept in the EU: the core is MIT-licensed and the EU cloud region is in Ireland. The Hobby plan includes 50,000 units a month at no charge, enough to try it on a real workload.
▸ WHAT TO KNOW FIRST
Self-hosting is not a single container: it needs PostgreSQL, ClickHouse, Redis or Valkey, and blob storage. Some add-on features need a license key even when self-hosted. On the cloud plans, usage beyond the included units is billed per 100,000 units, so the bill follows trace volume.