Library / SDK
Observability & Evaluation
lighteval
1All-in-one 2toolkit 3for 4evaluating 5language 6models
the six Ws · specification
W1
Who
Hugging Face users and ML teams evaluating LLMs across multiple inference backends.
W2
What
A Python library for evaluating language models across vLLM, Transformers and Nanotron backends with hundreds of tasks.
W3
Where
Self-hosted library, runs locally, on Hugging Face Spaces, or in the cloud.
W4
When
Released by Hugging Face in 2024 and actively developed through 2026.
W5
Why
Consolidates fragmented evaluation tooling into one fast, extensible toolkit tied to the Hugging Face ecosystem.
W6
With
Requires Python and integrates with Hugging Face Transformers, Accelerate and vLLM.
W7
Watch
Open source under MIT, self-hosted, no credentials for local use, maintained by Hugging Face, over 2.5k GitHub stars.
alternatives
works with