GPT-5.3-Codex

gpt-5.3-codex · OpenAI

GPT-5.3-Codex is optimized for agentic coding tasks in Codex or similar environments. GPT-5.3-Codex supports low, medium, high, and xhigh reasoning effort settings. If you want to learn more about prompting GPT-5.3-Codex, refer to our dedicated guide.

API Pricing

Input$1.75 / 1M tokens
Output$14 / 1M tokens
Cache read$0.175 / 1M tokens

Specifications

Context400K tokens
Modalitiestext, image, PDF
CapabilitiesThinking, Streaming, Tool calling, Web search, Structured outputs, Prompt caching

Frequently asked questions

What is GPT-5.3-Codex?

GPT-5.3-Codex is optimized for agentic coding tasks in Codex or similar environments. GPT-5.3-Codex supports low, medium, high, and xhigh reasoning effort settings. If you want to learn more about prompting GPT-5.3-Codex, refer to our dedicated guide.

What is the context length of GPT-5.3-Codex?

GPT-5.3-Codex has a 400,000 token context window.

How much does GPT-5.3-Codex cost?

On AIHubMix, GPT-5.3-Codex costs $1.75 per million input tokens and $14 per million output tokens. Cached input reads are billed at $0.175 per million tokens.

What modalities does GPT-5.3-Codex support?

GPT-5.3-Codex accepts text, image and PDF input.

What capabilities does GPT-5.3-Codex support?

GPT-5.3-Codex supports thinking, function calling and structured outputs. Per-protocol parameter support is listed in the capability table on this page.

How do I call GPT-5.3-Codex via API?

GPT-5.3-Codex is available through the AIHubMix unified API. The API is OpenAI-compatible: point your OpenAI SDK at https://aihubmix.com/v1, use your AIHubMix API key, and set the model name to gpt-5.3-codex — no other code changes needed.

Who created GPT-5.3-Codex?

GPT-5.3-Codex is developed by OpenAI. AIHubMix aggregates it alongside models from other providers behind one API and one bill.

When was GPT-5.3-Codex released?

GPT-5.3-Codex was released on February 5, 2026 by OpenAI.

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Use GPT-5.3-Codex via the AIHubMix unified API — one interface for every major LLM.