Fast facts: GPT-5's performance with reduced hallucinations

gpt-5-thinking has a hallucination rate 65% smaller than OpenAI o3.

gpt-5-main has a hallucination rate 26% smaller than GPT-4o.

gpt-5 models have significantly lower hallucination rates in both browsing settings.

gpt-5-thinking produces 5 times fewer factual errors than OpenAI o3.

gpt-5 models improve factual correctness on complex, open-ended prompts.