Tutorials, deep dives and product notes — built for developers.
From 33.4% Verified to 93.9% — Fable 5 breaks 90%. GPT-5.5's 47-day Terminal-Bench reign ends. Track 27 months of AI coding progress with new charts. Updated June 9, 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.