Pick Langfuse if
teams shipping LLM apps who need traces and a cost tile, not another chat UI.
Read the Langfuse pageLangfuse vs TruLens
Our take
Pick Langfuse if you're on a team shipping LLM apps who need traces and a cost tile, not another chat UI. Pick TruLens if you're on a rAG team who will run TruLens locally at $0 (you bring compute and judge-model keys) — not Arize first unless they want hosted Signal at $50. Skip Langfuse if you're people who only want a gateway (LiteLLM) or a framework (LangChain) without an observability SKU.
Best for
Langfuse Debug and cost-track generations
TruLens Prove a retrieval fix with public $0
Free plan
Langfuse $0 · for the MIT core. ee/ is not the community license
TruLens $0 · local dashboard. You pay your own LLM judge tokens and machines
Lowest paid
Langfuse Enterprise $2/mo
TruLens Not published by the vendor
Next step up
Langfuse Core $29/mo
TruLens
Coding agent
Langfuse
TruLens Instrumentation
Runs where
Langfuse Local or hosted
TruLens Hosted
Watch out
Langfuse Hobby is two users and 30-day retention
TruLens $0 is the library, not judge tokens
Last checked
Langfuse 2026-10-19 · langfuse.com/pricing
TruLens 2026-10-27 · trulens.org
Which one, then?
Pick TruLens if
rAG teams who will run TruLens locally at $0 (you bring compute and judge-model keys) — not Arize first unless they want hosted Signal at $50.
Read the TruLens page