Is Langfuse free for commercial use? Yes. Everything in the Langfuse server repository outside its ee folders is under the MIT license, which lets you use, modify, embed and resell the software in commercial products without paying, as long as you keep the copyright notice. What is not free is a short list of enterprise modules for self hosted deployments (SCIM, audit logs, data retention policies and a few admin features), which need a paid license key, and Langfuse Cloud beyond its free Hobby allowance.
That answer surprises people who remember Langfuse's older open core split, so this guide walks through the license text itself, what changed in June 2025, which features sit behind a key, how the cloud plans fit in, and how Langfuse compares with commercial and source available tracers. It is a plain reading of public documents as of October 24, 2026, not legal advice. If your company has a legal team that reviews licenses, send them the two license files linked below.
Is Langfuse free for commercial use? The short version
| Way you use Langfuse | Free for commercial use? | What to know |
|---|---|---|
| Self host the MIT core | Yes | No usage caps, unlimited users, same stack as the cloud |
| Fork it, modify it, ship it in a paid product | Yes | Keep the MIT copyright and permission notice |
| Python and JavaScript SDKs | Yes | Both are MIT licensed |
| Enterprise modules when self hosting | No | Need a Langfuse Enterprise license key |
| Langfuse Cloud Hobby plan | Yes, within limits | 50,000 units a month, 30 days of data, 2 users |
| Langfuse Cloud Core, Pro or Enterprise | Paid | From 29 dollars a month |
In spoken terms: the software is free for any business to run, and the paid parts are the hosted service and a set of enterprise controls.
What the Langfuse license actually says
The LICENSE file in the Langfuse repository splits the code into two parts. Anything under the ee/, web/src/ee/, worker/src/ee/ and packages/shared/src/server/ee/ directories is governed by a separate enterprise license. Everything else is available under the MIT Expat license. Third party components keep their own licenses.
The MIT grant is the standard one. It gives anyone the right to "use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software" on one condition: the copyright notice and permission notice must be included in all copies or substantial portions. There is no clause about revenue, company size, number of users or hosted services. That is why MIT is one of the most permissive licenses approved by the Open Source Initiative, and why Langfuse's own handbook says you can "fork it, extend it, ship it, even in commercial products."
The copyright line now reads ClickHouse, Inc. ClickHouse acquired Langfuse in January 2026, and the announcement said there were no planned licensing changes and that self hosting stays a first class path (Langfuse joins ClickHouse). Nothing in the current license file contradicts that.
What the enterprise license allows
The ee/LICENSE file opens with a note that the core "can be used and run without infringing" it. The enterprise license then says the enterprise code may only be used if you have a valid Langfuse Enterprise License and agreement. Two details matter for builders:
- You may copy and modify the enterprise code for development and testing without a subscription.
- You may not otherwise copy, publish, distribute, sublicense or sell it, and any patches you write to it belong to Langfuse.
So the enterprise folders are visible source code, but they are not open source. If you fork Langfuse to build a product, the clean approach is to leave the ee directories untouched and unused.
What changed in June 2025
Before mid 2025, several features people now consider basic were commercial. On June 4, 2025, Langfuse published Doubling Down on Open Source, moving managed LLM as a judge evaluations, annotation queues, prompt experiments and the playground into the MIT core. The post says commercially licensed code is now limited to features for enterprise security and platform teams, and that regular SSO "is and continues to be MIT licensed."
This is the main reason older forum answers and comparison posts get the question wrong. If a source from 2024 tells you evaluations or the playground need a paid license, it is out of date.
Which Langfuse features need a license key
According to the self hosted license key docs, the following features require a key when you run Langfuse yourself:
- Project level role based access control
- Protected prompt labels
- Data retention policies
- Audit logs
- Server side data masking
- UI customization
- Organization creators
- Organization management API and SCIM
- Instance management API
- FIPS mode
You turn them on by setting LANGFUSE_EE_LICENSE_KEY on both the web and worker containers. Langfuse says enterprise self hosted deployments send limited telemetry for license compliance. If you remove the key later, the core keeps working, though settings made through enterprise controls can behave oddly, so the docs advise clearing them first.
What stays free: tracing for agents and chains, sessions, user tracking, token and cost tracking, prompt management and versioning, datasets, experiments, LLM as a judge evaluators, human annotation queues, custom dashboards, the public API, batch exports, and sign in with Google, Azure AD, GitHub or other SSO providers. The self hosted pricing page lists included usage as unlimited for the open source edition.
Will I run enterprise code by accident?
No. Langfuse's handbook says the enterprise packages are isolated and gated by the license key check, so the standard image without a key does not run enterprise code. That matters if your compliance team wants proof that you only use MIT code: you can point to the absence of the environment variable.
Langfuse Cloud: free plan and paid plans
The cloud is a separate question from the license. You do not need a license to use Langfuse Cloud; you need a plan. Per the Langfuse pricing page on October 24, 2026:
- Hobby: free, no credit card, 50,000 units a month, 30 days of data access, 2 users, community support. Langfuse describes it as great for hobby projects and proofs of concept.
- Core: 29 dollars a month, 100,000 units included, 8 dollars per extra 100,000 units, 90 days of data, unlimited users.
- Pro: 199 dollars a month, 3 years of data, higher rate limits, SOC 2 and ISO 27001 reports and a HIPAA ready region.
- Enterprise: 2,499 dollars a month, adding audit logs, SCIM, custom rate limits and SLAs.
A unit is any trace, observation or score you send. We read the Langfuse terms and found no clause that limits the Hobby plan to noncommercial work, so a small company can use it in production. The practical limits are the 30 day history, two seats and a General API rate limit of 30 requests a minute. Most teams outgrow those before they hit any legal question. For a worked cost comparison against a big monitoring vendor, see Datadog LLM Observability vs Langfuse.
What free self hosting really costs
Free license does not mean free to run. A Langfuse deployment has two application containers (web and worker) plus PostgreSQL, ClickHouse, Redis or Valkey, and S3 compatible blob storage. Langfuse's docs describe the same stack for open source, enterprise self hosting and the cloud, scaling from a single Docker Compose machine to a Kubernetes cluster without feature gates.
That means your real costs are compute, storage and the engineer hours to patch and upgrade it. Langfuse cuts releases several times a week. If nobody on your team wants to operate ClickHouse, the Core cloud plan is often cheaper than the time spent.
Two operational points for commercial deployments:
- Telemetry. The open source build sends aggregated usage telemetry by default, with no traces, prompts or customer data. Set
TELEMETRY_ENABLED=falseto turn it off. - Air gapped use. After the initial image pull, Langfuse does not need outbound network calls, so it can run in a closed network.
Langfuse vs commercial tools on licensing
When people compare Langfuse vs commercial tools, licensing is usually the first filter. Here is how the common alternatives differ, checked against each project's license file or docs on October 24, 2026.
| Tool | License | Self host for free? | Main commercial catch |
|---|---|---|---|
| Langfuse | MIT core plus enterprise folders | Yes | Enterprise security modules need a key |
| LangSmith | Proprietary | No | Self hosting is an Enterprise plan addon |
| Arize Phoenix | Elastic License 2.0 | Yes | You may not offer it to third parties as a hosted or managed service |
| Opik | Apache 2.0 | Yes | Apache adds patent and notice terms, no use limits |
| Helicone | Apache 2.0 | Yes | Same as Opik |
The Phoenix row is the one that trips up startups. The Elastic License 2.0 text in the Phoenix repository forbids providing the software to third parties as a hosted or managed service that exposes a substantial set of its features. Using Phoenix internally to trace your own product is fine; reselling Phoenix itself as a service is not. MIT has no such limit, so a consultancy or platform company can host Langfuse for clients.
LangSmith is a different model entirely. It is closed source, its free Developer plan covers one seat, and self hosting is only available on its Enterprise plan. We compare the two directly in Langfuse vs LangSmith, cover LangSmith API keys and limits in is the LangSmith API free?, and the self hosting tradeoffs with Phoenix in Langfuse vs Arize Phoenix. For the wider field, see our list of the best LLM observability tools.
A quick checklist before you ship
If you plan to use Langfuse inside a commercial product or service, these five checks cover almost every case:
- Confirm you run the standard image without
LANGFUSE_EE_LICENSE_KEY, unless you have bought a license. - If you forked the repository, keep the MIT notice in your distribution and do not ship changes to the
eedirectories. - Decide whether you need any key gated feature, especially audit logs or SCIM for enterprise customers. If yes, budget for a license or the cloud Enterprise plan.
- Check third party dependencies if your legal team scans licenses. Langfuse says it runs an automated license check on server changes to avoid non permissive dependencies.
- Turn off telemetry if your security policy requires no outbound calls.
Once tracing is in place, the next job is using those traces to measure quality. Our guide on how to evaluate LLM applications and the explainer on LLM as a judge pick up from there.
FAQ
Can I use Langfuse in a commercial SaaS product?
Yes. The MIT license allows commercial use, modification, sublicensing and sale. You can self host Langfuse to trace your own SaaS or even host it for clients. Keep the copyright notice and avoid the enterprise directories unless you hold a license.
Is Langfuse open source or open core?
Both descriptions fit. Langfuse calls itself open core: everything outside the ee folders is MIT licensed and OSI approved, while a small enterprise periphery uses a commercial license. Since June 2025 that periphery covers only enterprise security and platform team features.
Is the Langfuse Cloud Hobby plan allowed for business use?
We found nothing in the Langfuse terms restricting the Hobby plan to personal or noncommercial use. Its limits are practical: 50,000 units a month, 30 days of data and two users. Langfuse markets it for hobby projects and proofs of concept.
Do I need a license for SSO when self hosting Langfuse?
No. Langfuse states that regular SSO is MIT licensed. SCIM user provisioning, project level roles, audit logs and data retention policies are the enterprise features that need a key.
Did the ClickHouse acquisition change the Langfuse license?
Not as of October 24, 2026. ClickHouse acquired Langfuse in January 2026, and the announcement said no licensing changes were planned. The license file now names ClickHouse, Inc. as copyright holder but keeps the same MIT core and enterprise split.
Is the Langfuse SDK free to use commercially?
Yes. The Langfuse Python SDK and the JavaScript SDK are both MIT licensed, so you can bundle them in proprietary code.
