vectara/hallucination-leaderboard

"leaderboard Comparing LLM Performance at Producing Hallucinations when Summarizing Short Documents".

github.com/vectara/hallucination-leaderboard
vectara/hallucination-leaderboard homepage screenshot

About vectara/hallucination-leaderboard

The vectara/hallucination-leaderboard is an open-source GitHub repository that hosts a public leaderboard ranking large language models (LLMs) by their rate of hallucination when summarizing short documents. It uses Vectara's Hallucination Evaluation Model (HHEM) to generate standardized, comparable metrics for each tested model, with planned regular updates as both the evaluation tool and the set of evaluated LLMs are updated over time.

The leaderboard reports four core metrics for every listed model: hallucination rate, factual consistency rate, answer rate, and average summary length in words. An interactive version of the leaderboard is hosted on Hugging Face, and archived versions of previous leaderboard iterations are available for users who want to reference older data. The repository includes supporting files including a citation guide, open-source license, and README for users seeking to access or reuse the dataset.

Key features

  • Ranks LLMs by hallucination rate when summarizing short documents
  • Uses Vectara's HHEM for standardized hallucination evaluation
  • Tracks hallucination rate, factual consistency, answer rate, and summary length per model
  • Interactive version hosted on Hugging Face for easier browsing
  • Archived previous leaderboard versions available for reference
  • Open-source repository with citation guide and license included
Best for: It is most useful for AI researchers, developers, and teams evaluating LLM performance for short-document summarization tasks.
Good for
  • Open-source and freely accessible to all users
  • Uses a standardized evaluation model for consistent cross-model comparisons
  • Includes multiple relevant performance metrics per tested LLM
  • Planned regular updates to reflect new models and evaluation improvements
Watch out for
  • Only evaluates LLM performance on short-document summarization tasks, not other use cases
  • Results are tied to Vectara's proprietary HHEM evaluation methodology

vectara/hallucination-leaderboard at a glance

Type
Open-source project
Pricing
Not confirmed. Check the site
Open source
Yes · Source code
Language
English
Last checked
Oct 5, 2026 · Online when checked
Listed
Oct 5, 2026

vectara/hallucination-leaderboard alternatives

Tools and sites you could use instead, ranked by how closely they match.

All 24 alternatives

Popular in Open Data & Datasets

Well-known listings from the same topic.

All 976

vectara/hallucination-leaderboard FAQ

What is the vectara/hallucination-leaderboard repository?
It is an open-source GitHub repository hosting a public leaderboard that ranks LLMs by their hallucination rate when summarizing short documents, using Vectara's HHEM evaluation model.
What metrics are included in the hallucination leaderboard?
The leaderboard reports four metrics per tested model: hallucination rate, factual consistency rate, answer rate, and average summary length in words.
Is the hallucination leaderboard free to access?
Yes, the repository and all its associated data are open-source and freely available to all users with no associated costs.
Are previous versions of the leaderboard available?
Yes, archived versions of earlier leaderboard iterations are linked in the repository for users who want to reference older data.
Is something wrong or out of date?

Tell us and an editor will check it.

Own this website?

Claim the listing and suggest updates yourself. An editor checks every claim first.

Claim this listing