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GPT 5.3 Codex

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GPT-5.3 Codex is a faster, more token-efficient coding model built for real-time iteration and agentic development at scale.
GPT-5.3 Codex is a faster, more token-efficient coding model built for real-time iteration and agentic development at scale.

GPT 5.3 Codex is an AI model from OpenAI, available on ZeroTwo. It costs $1.75 per million input tokens and $14.00 per million output tokens, has a 400,000-token context window, can return up to 128,000 output tokens, and has a knowledge cutoff of August 31, 2025.

Price
$1.75 • $14.00
Input • Output

GPT-5.3 Codex is a faster, more token-efficient coding model built for real-time iteration and agentic development at scale.

400,000 context window
128,000 max output tokens
August 31, 2025 knowledge cutoff
Reasoning token support
Pricing
Pricing is based on the number of tokens used. For tool-specific models, like search and computer use, there's a fee per tool call. See details in the pricing page.
Text tokens
Per 1M tokens
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Batch API price
Input
$1.75
Cached input
Output
$14.00
Quick comparison
Input
Cached input
Output
GPT 5.3 Codex
$1.75

Questions

How much does GPT 5.3 Codex cost?

GPT 5.3 Codex is priced at $1.75 per million input tokens and $14.00 per million output tokens. On ZeroTwo it is included in your plan's credits rather than billed per token.

What is GPT 5.3 Codex's context window?

GPT 5.3 Codex accepts up to 400,000 tokens of context and can return up to 128,000 output tokens.

What is GPT 5.3 Codex's knowledge cutoff date?

GPT 5.3 Codex has a training knowledge cutoff of August 31, 2025. For anything later than that, use a model with web search enabled.

Can I use GPT 5.3 Codex for free?

You can try GPT 5.3 Codex on ZeroTwo's free plan, which includes a monthly credit allowance across every model in the catalogue. Heavier use moves to a paid plan rather than a per-token bill.