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.

The original poster tested various AI models, including Sonnet 4.6, Opus 4.6, Opus 4.7, and ChatGPT 5.3, using the same prompt.