OpenLLMetry vs Prompt flow
A side-by-side comparison of two self-hosted self-hosted ai options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | OpenLLMetry | Prompt flow |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 91 · Excellent | 78 · Good |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Apache-2.0 | MIT |
| Language | Python | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 2,048 MB |
| Deployment | docker, source | docker, source |
| GitHub stars | ★ 7,445 | ★ 11,244 |
| First released | 2023 | 2023 |
| Replaces | LangSmith, Datadog LLM Observability | LangSmith, Vertex AI |
What are OpenLLMetry and Prompt flow?
OpenLLMetry
OpenLLMetry is a set of OpenTelemetry extensions from Traceloop that add observability to LLM applications. It instruments calls to model providers and vector databases so traces and metrics can be sent to any self-hosted backend.
- OpenTelemetry-based tracing
- Instruments popular LLM SDKs
- Vendor-neutral export
- Vector database instrumentation
Prompt flow
Prompt flow is an open-source development toolkit from Microsoft for building, testing, and evaluating LLM-powered applications. It provides a visual flow editor, batch evaluation, and tooling to debug prompt pipelines locally.
- Visual flow authoring
- Batch evaluation runs
- Local debugging tools
- VS Code extension
OpenLLMetry vs Prompt flow: key differences
Both projects are written in Python. Licensing differs — Apache-2.0 for OpenLLMetry versus MIT for Prompt flow. OpenLLMetry is the lighter option, starting around 512 MB of RAM against 2,048 MB for Prompt flow.
Why pick each one
Choose OpenLLMetry if…
- Released under the Apache-2.0 license
- First-class Docker support for quick deployment
- Mature project with 7.4k GitHub stars
- Written in Python
Choose Prompt flow if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Mature project with 11.2k GitHub stars
- Written in Python
Frequently asked questions
Is OpenLLMetry or Prompt flow better?
Neither is universally better. Prompt flow has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are OpenLLMetry and Prompt flow free and open-source?
Yes. OpenLLMetry is licensed under Apache-2.0 and Prompt flow under MIT. Both can be self-hosted at no software cost.
Can I run OpenLLMetry and Prompt flow with Docker?
OpenLLMetry: yes. Prompt flow: yes.
Which is lighter on resources, OpenLLMetry or Prompt flow?
OpenLLMetry has the smaller minimum footprint at 512 MB of RAM, compared to about 2,048 MB for Prompt flow. Real-world usage depends on library size, user count, and enabled features.