Engineering
Claude Opus 4.6 vs GPT-5.3 Codex: The Same-Day Drop That Split the Developer World
On February 5th, at 6:40 PM Eastern, Anthropic dropped Claude Opus 4.6. Twenty minutes later, OpenAI fired back with GPT-5.3 Codex. Twenty minutes. That's not a coincidence. That's a knife fight. And now every developer on earth is staring at two tabs, wondering