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GPT-5.1-CodexAPI
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows.
Prices update automatically — checked daily against provider list prices.
- $3.44 per 1M tokens, assuming 3 input for 1 output the convention used by Artificial Analysis
- cheaper than 35% of the 192 commercial models tracked here
- 52 of 88 OpenAI models tracked here, from cheapest
Benchmarks & performance
Independent benchmark scores for GPT-5.1-Codex, measured by Artificial Analysis. Higher is better. Measurement mode: high.
Models at this level cost $1.72 per 1M tokens (median of 25) — this one costs $3.44.
Cheaper and better on this index: Grok 4.6 · GPT-5.6 Sol (batch) · GLM 5.3 and 63 more
About this model
GPT-5.1-Codex is a commercial AI model by OpenAI. The specifications below are tracked automatically: pricing is refreshed daily 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 35.6 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 25.7%, Long Context Reasoning 69%, 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.