OpenAI releases GPT-5.3-Codex just moments after Anthropic dropped Claude Opus 4.6

Following multiple rumors from earlier today, Anthropic finally released Claude Opus 4.6. OpenAI, being a fierce rival, has followed up the launch with its GPT‑5.3‑Codex release. The launch came moments after Anthropic dropped its model. If you haven’t checked out Opus 4.6, make sure to read our news piece here. GPT‑5.3‑Codex isn’t just faster, it’s more collaborative, too GPT‑5.3‑Codex is OpenAI’s latest bet towards agentic coding, which combines the coding prowess of GPT‑5.2‑Codex with the reasoning and professional knowledge of GPT‑5.2. It’s also 25% faster, meaning allows it to handle long-running tasks like research, tool use, and complex execution. Much