Model Details
Owner
OpenAI
Released
Nov 2025
Status
Active
Context Length
400K
Max Output
128K
Provider
OpenAI
Where is gpt-5.1-codex-max a perfect fit?
gpt-5.1-codex-max is built for long-horizon, autonomous coding workflows where models need to think, act, and iterate over extended periods. Ideal for:
- Multi-hour or continuous coding agents handling large projects
- Full-repo refactoring, debugging, and test-driven development
- Autonomous PR creation, review, and iteration loops
- Complex engineering workflows involving multiple tools and environments
- Large-scale system design and cross-file reasoning
- Async development (define task → model executes over hours)
- Multi-hour or continuous coding agents handling large projects
- Full-repo refactoring, debugging, and test-driven development
- Autonomous PR creation, review, and iteration loops
- Complex engineering workflows involving multiple tools and environments
- Large-scale system design and cross-file reasoning
- Async development (define task → model executes over hours)
Quick Model Estimate
Your GPT-5 Cost Estimate
💰 Total Cost
USD 3.00
for 1000 input + 1000 output tokens
📥 Input (1000 × $1.250000)
USD 1.5000
📤 Output (1000 × $10.000000)
USD 1.5000
Cost Breakdown
📥 Input 50%
📤 Output 50%
Prices updated daily from official provider data.
Pricing
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 OpenAI
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Text | $1.2500 | $10.0000 | 400,000 tokens | 2026-03-26 | → |
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OpenAI
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Text | $2.5000 | $20.0000 | 400,000 tokens | 2026-03-26 | → |