GPT-5.1-Codex

OPENAI Developer Architecture Profile

Intelligence (ELO)1481Chatbot Arena Verified

Max Context400,000Tokens

API Cost / 1M$11.25Blended Prompt + Completion

Model Capabilities

Coding & Logic
Fictional

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....

Granular Pricing Matrix

Input Tokens (Prompt)$1.25 / 1M

Output Tokens (Completion)$10.00 / 1M

Pricing data via OpenRouter. Sync: 8/1/2026

Evaluate Competitors

VS Engine MatchupGPT-5.1-Codex vs MoonshotAI: Kimi K3 VS Engine MatchupGPT-5.1-Codex vs Google: Nano Banana 2 Lite (Gemini 3.1 Flash Lite Image)VS Engine MatchupGPT-5.1-Codex vs Sao10K: Llama 3.3 Euryale 70B VS Engine MatchupGPT-5.1-Codex vs OpenAI: o1 VS Engine MatchupGPT-5.1-Codex vs OpenAI: GPT-4o-mini (2024-07-18)VS Engine MatchupGPT-5.1-Codex vs Google: Nano Banana Pro (Gemini 3 Pro Image)