LLMOps and observability
Langfuse: review, pricing, data and alternatives
Langfuse tracks agent calls and steps, measures model costs and usage, and evaluates responses. It serves people who want to manage instruction versions and compare trials on datasets. A free tier exists; the first paid plan costs $29 per month. Access and transparency score: 95/100, #1 of 18 in its category.
What is Langfuse?
Langfuse tracks agent calls and steps, measures model costs and usage, and evaluates responses. It serves people who want to manage instruction versions and compare trials on datasets.
According to its documentation, Langfuse lets you:
- track an agent's calls and steps
- measure model costs and usage
- evaluate response quality
- manage multiple versions of instructions
- compare trials on datasets
We file it under LLMOps and observability, the category of tools to evaluate, monitor and debug AI apps, and it also overlaps with developer tools. The category lists 18 verified tools on this site.
The publisher is ClickHouse, Inc., based in United States. The service launched in 2023, which gives it some track record.
Who is it for?
It is mostly useful to these profiles: developers, data analysts, and researchers. The need it covers is simple to state: evaluate, monitor and debug AI apps.
Langfuse is a good candidate if:
- you want to try before paying
- you plan to connect it to your tools or automations through its API
- you want to read the code or host it yourself
Before deciding, run a trial on a real task and measure the time saved: it is the only criterion that really counts.
How much does Langfuse cost?
Pricing model: open source (public code). A free plan is offered, usually limited in volume or features.
The first paid plan costs $29 per month (Core on Langfuse Cloud; free self-hosting is possible), according to the pricing page, checked on October 24, 2026.
Per month, that is cheaper than the category median ($49 per month, based on tools with a published price).
To estimate what the same work would cost done directly with an AI model, use our API price calculator. Prices change often: always check the official site before subscribing.
Data and privacy
According to its privacy policy, data is processed in several regions depending on the plan.
Exporting your content: yes (details on the official site). Being able to get your data back makes switching tools easier later.
Three habits apply to every AI tool:
- turn off the use of your content for training if the option exists
- use a work account separate from your personal account
- review everything the tool produces before publishing or sending it
Platforms, languages and API
Langfuse runs on: web browser and API.
Interface languages are not specified.
A public API lets you call it from your own programs or an automation tool, and plug it into an AI agent.
The source code is public: langfuselangfuse/langfuse.
How we scored it
Our 95/100 score does not judge output quality: it measures what can be publicly verified about access to the tool, its openness and how far the publisher can be trusted.
| Criterion | Points | What counts |
|---|---|---|
| Access | 25/30 | free tier, published price, French interface |
| Openness | 30/30 | API, data export, open code |
| Trust | 40/40 | identified publisher, declared hosting, age, presence in reference lists |
The full calculation is explained on our method page.
Comparison with alternatives
Langfuse against other tools in the lLMOps and observability category:
| Tool | Free | Entry price | API | Score |
|---|---|---|---|---|
| Langfuse | Yes | $29 per month | Yes | 95 |
| LangSmith | Yes | $39 per month | Yes | 85 |
| Opik | Yes | $19 per month | Yes | 83 |
| Arize Phoenix | Yes | not published | Yes | 81 |
| Overmind | Yes | $120 per month | Yes | 78 |
| MLflow | Yes | not published | Yes | 78 |
| Respan | Yes | $199 per month | Yes | 71 |
| Prisma AIRS AI Gateway — Portkey | Yes | $49 per month | Yes | 71 |
Verdict
Langfuse is among the most accessible and transparent tools in its category.
Strengths
- Free tier to try it
- Cheaper than its category median
- Public API
- Public source code
- Established since 2023
Alternatives
Categories and jobs
Learn more
Frequently asked questions
Is Langfuse free?
Yes, a free plan exists, with usage limits. The first paid plan costs $29 per month.
Where is Langfuse data stored?
According to the publisher, in several regions depending on the plan.
Does Langfuse have an API?
Yes, a public API is documented.
What are the alternatives to Langfuse?
In the same category: LangSmith, Opik, Arize Phoenix, and Overmind.
Langfuse or LangSmith: which one to choose?
Langfuse starts at $29 per month, LangSmith at $39 per month and our score is 95/100 for Langfuse and 85/100 for LangSmith. Try both on the same task before paying.
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Neutrality. No affiliate links. No vendor pays to be reviewed, rated or ranked. Reviews are directed by François Chollet, neutral and factual, and every data point is dated and sourced. How we score