The openai/gpt-5-high-2025-08-07 model achieved a hallucination rate of 15.1%, a factual consistency rate of 84.9%, an answer rate of 99.9%, and an average summary length of 162.7 words as of March 20, 2026.

Authors

• Person: Not available Organization: Vectara
  vectara/hallucination-leaderboard - GitHub

Sources

• vectara/hallucination-leaderboard - GitHub github.com Vectara via serper

Referenced by nodes (4)

• hallucination rate concept
• answer rate concept
• factual consistency rate concept
• summary length concept