GPT-5.3-Codex
by OpenAI
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 k
Models
GPT-5.3-Codex
Added 10 July 2026
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-codexDocs
OpenRouter id: openai/gpt-5.3-codex
Benchmarks
- Intelligence Index (artificial-analysis): 32.5 index
- Design Arena androidnative (other): 1084 elo · #30
- Design Arena fullstack (other): 983 elo · #42
- Design Arena godotgamedev (other): 1124 elo · #27
- Design Arena mobileapps (other): 1053 elo · #44
Notes
GPT-5.3-Codex is listed in the EDNA Models directory from the OpenRouter catalogue.
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