Claude Opus 4.7 shows clear improvement over Opus 4.6 in some long context reasoning measures but is a regression in others, such as finding the fourth poem across 1 million tokens.

Claude Opus 4.7 scores worse than Opus 4.6 on Simple Bench, a benchmark designed to test common sense.

Claude Opus 4.7 underperforms Opus 4.6 and Mythos Preview in cybersecurity vulnerability reproduction.