GPT-5.3-Codex

Overview

GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...

How to use / API access

Call via OpenRouter with model id `openai/gpt-5.3-codex`.

• openrouter · openai/gpt-5.3-codex Docs

OpenRouter id: openai/gpt-5.3-codex

Benchmarks

• Design Arena androidnative (other) : 1084 elo · #21
• Design Arena fullstack (other) : 1043 elo · #31
• Design Arena godotgamedev (other) : 1166 elo · #15
• Design Arena mobileapps (other) : 1127 elo · #28

Notes

GPT-5.3-Codex is listed in the EDNA Models directory from the OpenRouter catalogue.