Claude Opus 4.8 review: 8-0 over GPT-5.5, near-split with Opus 4.7 We ran 12 coding, math, and data tasks through Opus 4.8, Opus 4.7, and GPT-5.5 via LLMTest. Opus 4.8 swept GPT-5.5 but split with its predecessor. May 29, 2026 · 8 min read hotclaudebenchmarks