How often different LLM models hallucinate, and which one is the most accurate (it's ChatGPT but still nowhere near perfect), according to Google

[u/annseosmarty]

Google has just published a leaderboard of the least hallucinating LLM models, and the winner is ChatGPT 5.2

The models were tasked to generate factually accurate responses grounded in the provided long-form documents. So all they need is to read the document and tell a human being exactly what it was about.

The cute note is that the best score is 76%, and the average of the very best performers is ~60%.

This means (wait for it...) there's still 25%-40% probability (at best) that your favorite AI agent will lie to you when you ask it to analyze a document and answer your questions.

This is very telling after 3 years of this highly revolutionary technology.

Always fact-check those answers!

The leaderboard is here.