The Context Window Lie: How Well AI Models Actually Use 1M Tokens in 2026
Every AI model claims a 1M-token context window. But only GPT-5.5 and Claude Opus 4.6 actually use it. We analyzed MRCR v2, NIAH-2, and Graphwalks to show the 60-point gap between the best and worst "1M-capable" models — and which one to trust for long-context coding.
· CodingFleet