Langfuse
Open-source LLM observability, tracing and evals.
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About Langfuse
Langfuse is listed in our evals & observability category and is aimed at builders. Open-source LLM observability, tracing and evals. Pricing, as the maker states it: Open source + paid cloud. Maturity: Mature. We last checked the official link on 2026-10-14.
What is Langfuse?
Langfuse is an open-source LLM engineering platform that helps teams develop, monitor, evaluate and debug AI applications together.
It can be self-hosted in minutes, with a paid cloud as well.
Sources: the official README and our directory listing, checked 2026-10-18. Official site: langfuse.com.
Who is Langfuse for?
Teams building LLM apps who want open-source tracing and evals.
Langfuse at a glance
- Open source: Yes (MIT, except the ee/ directories (commercial licence))
- GitHub: langfuse/langfuse · 36,132 stars (as of Oct 21, 2026)
Key features
- Tracing
- Evaluations
- Prompt management
- Self-host or cloud
Langfuse pricing
- Hobby: Free
- Core: $29/mo · 100k units a month, 90 days data access
- Pro: $199/mo · unlimited history
- Enterprise: $2499/mo
Additional usage is $8 per 100k units. A Teams add-on is $300/mo. Langfuse can also be self-hosted from its GitHub repo.
Source: official pricing page, checked Oct 18, 2026. Prices change; check the source before buying.
Langfuse FAQ
What is Langfuse?
Langfuse is an open-source LLM engineering platform that helps teams develop, monitor, evaluate and debug AI applications together.
Who is Langfuse for?
Teams building LLM apps who want open-source tracing and evals.
Is Langfuse free?
Yes. Langfuse has a free option (Hobby), according to its pricing page (checked Oct 18, 2026).
How much does Langfuse cost?
As of Oct 18, 2026, Langfuse's official pricing page lists: Hobby: Free; Core: $29/mo; Pro: $199/mo; Enterprise: $2499/mo. Additional usage is $8 per 100k units. A Teams add-on is $300/mo. Langfuse can also be self-hosted from its GitHub repo.
Is Langfuse open source?
Yes. Langfuse is released under MIT, except the ee/ directories (commercial licence), according to its GitHub repository.
What are alternatives to Langfuse?
Similar tools include MLflow, Arize Phoenix, Laminar, Helicone, Respan and Future AGI.
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Langfuse alternatives
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Future AGI
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