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GPT-5.1-CodexAPI
GPT-5.1-Codex (OpenAI): live API pricing, context window and the best open-source alternatives, tracked daily by olud.ai.
Prices update automatically — checked hourly against provider list prices.
Benchmarks & performance
Independent benchmark scores for GPT-5.1-Codex, measured by Artificial Analysis. Higher is better. Measurement mode: high.
About this model
GPT-5.1-Codex is a commercial AI model by OpenAI. The specifications below are tracked automatically: pricing is refreshed hourly from public list prices, so the numbers on this page reflect the current cost of using the model through its API.
Frequently asked questions
What is GPT-5.1-Codex?
GPT-5.1-Codex is an AI language model from OpenAI. It is a proprietary model, available through an API. It scores 34.7 on the Artificial Analysis intelligence index.
Is GPT-5.1-Codex free?
GPT-5.1-Codex is not free: it costs $1.25 per million input tokens and $10 per million output tokens. Open-weight alternatives can be self-hosted at no per-token cost.
What is GPT-5.1-Codex good at?
Independent benchmarks from Artificial Analysis give it GPQA 86%, MMLU-Pro 86%, Humanity's Last Exam 23.4%, Long Context Reasoning 67.3%, LiveCodeBench 84.9%, SciCode 40.2%, AIME 2025 95.7%, IFBench 70%, τ²-Bench 83%, Terminal-Bench Hard 34.8%. It is particularly used for mathematical reasoning.