Anthropic and OpenAI release dueling AI models on same day

Businessinsider reports that Anthropic and OpenAI released new AI models on the same day, escalating a rivalry between the two companies. Anthropic unveiled Claude Opus 4.6, which the company says improves office productivity and coding tasks and expands the context window to handle longer documents and more complex projects in a single session.

OpenAI introduced GPT-5.3-Codex, which it says runs faster, uses fewer computing resources, can generate and manage complex software from English instructions, and is available alongside a stand-alone Codex desktop app. Sam Altman and Sholto Douglas appeared back-to-back on the "TBPN" podcast.