The deciding difference is operational: promptfoo can run on infrastructure you control, Pydantic Logfire cannot. If that constraint is real for you, it settles the choice before anything else is considered.
OpenTelemetry observability with first-class Python and Pydantic AI support.
Local eval and red-team harness that runs in CI. No account needed.
Its red-team mode doubles as your prompt-injection regression suite.
| Pydantic Logfire | promptfoo | |
|---|---|---|
| Licence | Open source | Open source |
| Pricing | freemium | open source |
| Self-hostable | No | Yes |
| Languages | Python, TypeScript | TypeScript, Python |
| Install | pip install logfire | npm install -g promptfoo |
| Keys required | LOGFIRE_TOKEN | None |
The deciding difference is operational: promptfoo can run on infrastructure you control, Pydantic Logfire cannot. If that constraint is real for you, it settles the choice before anything else is considered. Pydantic Logfire: OpenTelemetry observability with first-class Python and Pydantic AI support. promptfoo: Local eval and red-team harness that runs in CI. No account needed.
Pydantic Logfire is a hosted service only. promptfoo can run on your own infrastructure.
Pydantic Logfire is open source (freemium). promptfoo is open source (open source).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/logfire-vs-promptfoo