factuality benchmark
LongFact
LongFact evaluates factual precision over long-form generations containing many individual claims. Each claim is extracted and verified, and the model is scored on claim-level precision, measuring whether extended responses introduce unsupported or false statements.
Updated Aug 7, 2026
Published models1
Registry coverage1
MetricScore
EvidenceB
LongFact leaderboard
Sorted by the source-provided rank. Higher score is better according to the registry.
| 1 | MI | 98.0% | 100.0% | 1 | C |
LongFact highlights
The top published results on this benchmark's own scale.
What is LongFact?
Definition and scoring fields from the benchmark registry.
LongFact evaluates factual precision over long-form generations containing many individual claims. Each claim is extracted and verified, and the model is scored on claim-level precision, measuring whether extended responses introduce unsupported or false statements.
Scores are shown in ratio. The current registry marks this benchmark as not independently verified with evidence level B.
- Family
- LongFact
- Modality
- text
- Primary category
- factuality
- Score direction
- higher
- LLMBoard eligible
- No
- Evaluation key
- longfact|llm-stats-current
Source-native results are preserved. Eligibility for the overall LLMBoard score is a separate policy decision.
FAQ
Common questions about LongFact.
Which model scores highest on LongFact?
MAI-Thinking-1 is currently ranked first with 98.0%.
What does LongFact measure?
LongFact evaluates factual precision over long-form generations containing many individual claims. Each claim is extracted and verified, and the model is scored on claim-level precision, measuring whether extended responses introduce unsupported or false statements.
Is a higher score better?
Yes. Higher values rank better for this benchmark.
How many models are compared?
1 unique published model results are currently shown.
Does this benchmark affect the overall score?
This benchmark is preserved as source-native evidence but is not eligible for the current overall score.