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GPT-5.3-CodexAPI
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.
Prices update automatically — checked daily against provider list prices.
- $4.81 per 1M tokens, assuming 3 input for 1 output the convention used by Artificial Analysis
- cheaper than 25% of the 192 commercial models tracked here
- 62 of 88 OpenAI models tracked here, from cheapest
Benchmarks & performance
Independent benchmark scores for GPT-5.3-Codex, measured by Artificial Analysis. Higher is better. Measurement mode: xhigh.
Models at this level cost $2.22 per 1M tokens (median of 10) — this one costs $4.81.
Cheaper and better on this index: GPT-5.6 Sol · Grok 4.6 · GPT-5.6 Sol (batch) and 29 more
About this model
GPT-5.3-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-5.3-Codex?
GPT-5.3-Codex is an AI language model from OpenAI. It is a proprietary model, available through an API. It scores 45.5 on the Artificial Analysis intelligence index.
Is GPT-5.3-Codex free?
GPT-5.3-Codex is not free: it costs $1.75 per million input tokens and $14 per million output tokens. Open-weight alternatives can be self-hosted at no per-token cost.
What is GPT-5.3-Codex good at?
Independent benchmarks from Artificial Analysis give it GPQA 91.5%, Humanity's Last Exam 42.5%, Long Context Reasoning 78.3%, SciCode 53.2%, IFBench 75.4%, τ²-Bench 86%, Terminal-Bench Hard 53%.
How fast is GPT-5.3-Codex?
It generates about 125.8 tokens per second, with a median 40.06s delay before the first token. Measured independently by Artificial Analysis.