Last week, OpenAI and Anthropic dropped their respective coding models-GPT-5.3-Codex and Claude Opus 4.6-both of which represented significant leaps in AI coding capabilities. GPT-5.3-Codex showed markedly higher performance on coding benchmarks than earlier models, while Opus 4.6 introduced a feature that lets users deploy autonomous AI agent teams that can tackle different aspects of complex projects simultaneously. Both models can write, test, and debug code with minimal human intervention-even iterating on their own work and refining features before presenting results to developers.
