Langfuse vs TruLens

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

Tagline

Langfuse

Open-source LLM observability, prompt management, and evaluation in one platform.

TruLens

Open-source evaluation and tracing framework for LLM apps and agents, built on OpenTelemetry.

Pricing

Langfuse

Freemium· Free self-host & Hobby tier; Core $29/mo, Pro $199/mo, Enterprise $2,499/mo

TruLens

Free· Free, open source (Apache-licensed Python package)

Free trial

Langfuse

Yes

TruLens

Yes

API

Langfuse

Yes

TruLens

Yes

Platforms

Langfuse

api

TruLens

apicliweb

Open source

Langfuse

Yes · NOASSERTION

TruLens

Yes · MIT

GitHub stars

Langfuse

35,207

checked 2026-09-29

TruLens

3,579

checked 2026-09-29

Last GitHub push

Langfuse

2026-09-29

TruLens

2026-09-29

First commit

Langfuse

2023-05

TruLens

2020-11

Company

Langfuse

—

TruLens

TruEra

Model used

Langfuse

Model-agnostic

TruLens

Multi-model (LLM-as-judge)

Best for

Langfuse

Pick Langfuse if you want production-grade LLM tracing, prompt versioning, and evals in one open-source tool you can self-host.

TruLens

Pick TruLens if you want a code-first, open-source way to trace and score LLM apps or agents without sending eval data to a hosted vendor.

Not for

Langfuse

Skip it if you just need a no-code prompt playground or you're not yet running LLM calls in production worth instrumenting.

TruLens

Skip it if you need a turnkey managed eval SaaS with a hosted UI, non-Python SDKs, or zero infra work.

Editorial score

Langfuse

7.3 / 10

TruLens

8.1 / 10

Use cases

Langfuse

llm-observabilityprompt-managementllm-evaluationagent-tracingrag-debugging

TruLens

llm-evaluationrag-evaluationagent-tracingregression-testingobservability

Pros

Langfuse

Fully open source and self-hostable at no cost
Tracing, prompts, and evals in one platform instead of three
Built on OpenTelemetry with SDKs for Python and JS
Integrates with OpenAI SDK, LangChain, LlamaIndex, and 100+ libraries
Generous free Hobby tier with no credit card required

TruLens

Free and open source, no vendor lock-in on eval data
OpenTelemetry-native tracing plugs into existing observability stacks
Broad library of benchmarked feedback functions plus custom metrics
Framework-agnostic: works with LangChain, LlamaIndex, or raw SDK calls
Backed by Snowflake with active maintenance

Cons

Langfuse

Cloud pricing by 'units' is opaque until you instrument and measure
Self-hosting Postgres + ClickHouse stack is non-trivial to operate
Pro/Enterprise jump ($29 to $199 to $2,499) leaves a gap for mid-size teams

TruLens

Self-hosted library, no managed dashboard or hosted storage
LLM-as-judge metrics rack up model API costs you pay separately
Python-only SDK, no first-party JS/TS client

Website

Langfuse

langfuse.com

TruLens

www.trulens.org

Editorial score: rule-based, 0–10, from AI-assisted profile inputs (see /methodology) — not a user rating; “—” means unscored. “Not listed” means we have no record of it, not that it is absent. GitHub figures and prices carry the date they were checked or captured; prices are shown as published, unconverted.

Pick Langfuse if

✅ Fully open source and self-hostable at no cost
✅ Tracing, prompts, and evals in one platform instead of three
✅ Built on OpenTelemetry with SDKs for Python and JS
✅ Integrates with OpenAI SDK, LangChain, LlamaIndex, and 100+ libraries

Pick TruLens if

✅ Free and open source, no vendor lock-in on eval data
✅ OpenTelemetry-native tracing plugs into existing observability stacks
✅ Broad library of benchmarked feedback functions plus custom metrics
✅ Framework-agnostic: works with LangChain, LlamaIndex, or raw SDK calls

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