Opus 4.6 and ChatGPT 5.3-Codex Are Here and the Labs Are at War

Anthropic dropped Claude Opus 4.6 and OpenAI responded with GPT 5.3 Codex just 20 minutes later — the most intense head-to-head model release we've ever seen. Here's what each model brings, how they compare, and what the first reactions are telling us. In the headlines: Google and Amazon…