All Langfuse Product Features now Free Open-Source

Today, we’re excited to share a big milestone: all Langfuse product features are now open source under the MIT license.

The LLM landscape is evolving rapidly - and so are the tools and workflows that developers use to build and improve their LLM applications. To empower our community and invite deeper collaboration, we’ve decided to open source all previously commercial features of Langfuse.

That means you can now self-host features like:

• Managed LLM-as-a-Judge evaluations
• Annotation queues
• Prompt experiments
• LLM playground

All fully open under the MIT license.

If you're already self-hosting Langfuse, upgrade to the latest version to unlock these new features.

Why we’re doing this

Langfuse is building the open source LLM engineering platform - a platform to observe, evaluate, and improve LLM applications.

To truly serve the developer community, we believe the full dev cycle needs to be covered by open source. Features like evals and prompt experiments are table stakes in today’s LLMOps world. These shouldn’t be behind a paywall.

By removing commercial restrictions from key product features, we’re doubling down on transparency, adoption, and community collaboration. It lets us move faster together.

Our Open Source Journey

Langfuse started as an open source project, grounded in a few core principles:

• Developers should fully own and access their data
• Langfuse must integrate with any stack, framework, or model
• Teams should have the freedom to customize the platform for their workflows

That philosophy still guides us today - now with an even wider open-source surface.

While we continue to support enterprise needs (like SCIM, Audit Logs, and custom data retention policies), the core of Langfuse is now entirely OSS.

Langfuse in the Wild

Langfuse is growing fast:

• 7,000,000 SDK installs/month
• 5,500,000 Docker pulls
• 8,000 monthly active self-hosted instances

We’re constantly amazed by the scale and creativity of our community. We hope this move makes Langfuse even more accessible and extensible for all developers building with LLMs.

📌 Check out the self-hosting docs

🚀 Deploy with Terraform

Let us know what you're building - and how we can help make Langfuse even better.

✍️ By Clemens, Marc & Max