Claude Fable and Opus Models Dominate Code Generation, Outpacing Codex-Era Benchmarks

Anthropic's Claude models are rewriting software engineering performance standards, with the latest releases achieving unprecedented success on industry-standard coding benchmarks. Claude Fable 5 has reached 95.0% accuracy on SWE-bench Verified, while Claude Opus 4.7 scores 87.6%—marking a decisive shift away from earlier code-generation systems like OpenAI's Codex, which defined the baseline for AI-assisted programming.