Intelligence Index

Artificial Analysis released version 4.2 of its Intelligence Index after its original scoring showed GPT-6 Astra barely improving on its predecessor, contradicting Epoch AI's ranking of Astra as the top model out of 267 tested. The update adds two benchmarks, drops the saturated GPQA-Diamond, and increases private test weighting to 40 percent.

xAI's Grok 4.20 scores 48 on Artificial Analysis' Intelligence Index—6 points ahead of Grok 4 but trailing Gemini 3.1 Pro Preview and GPT-5.4 at 57. The model distinguishes itself with a 78% non-hallucination rate on the AA Omniscience test, the highest recorded across any model tested.