OpenAI
GPT-5.1-Codex
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows.
At a glance
- Input / 1M
- $1.25
- Output / 1M
- $10
- Context
- 400K
- Max output
- 128K
- Intelligence
- 23.7
- Released
- Nov 2025
Pricing
GPT-5.1-Codex API pricing
Per-token rates, plus what common tasks actually cost.
| Input tokensPer 1M tokens | $1.25 |
|---|---|
| Output tokensPer 1M tokens | $10 |
| Cached input (read)Per 1M tokens | $0.13 |
| Cache writePer 1M tokens | Not available |
| Web searchPer request | $0.01 |
Chat message
2K in, 500 out
$7.50
per 1,000 requests
Coding task
30K in, 4K out
$77.50
per 1,000 requests
Long document summary
150K in, 2K out
$207.50
per 1,000 requests
Benchmarks
GPT-5.1-Codex benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
23.7
Coding index
Not available
Agentic index
Not available
Specs
Context window and capabilities
What it can read, what it can write, and which API features it supports.
- Context window
- 400K tokens
- Max output
- 128K tokens
- Input types
- Image, Text
- Output types
- Text
- Reasoning effort
- High, Medium, Low
- Release date
- November 13, 2025
- Tool calling
- Structured outputs
- JSON mode
- Reasoning
- Temperature
- Stop sequences
- Deterministic seed
- Verbosity control
Compare
GPT-5.1-Codex vs other models
See how GPT-5.1-Codex stacks up head to head on price, benchmarks, and features.
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See comparisonAlternatives
GPT-5.1-Codex alternatives
Similar models worth considering, and where each one has the edge.
OpenAI
GPT-5.2
OpenAI
GPT-5.2-Codex
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FAQ
Frequently asked questions
How much does GPT-5.1-Codex cost?
GPT-5.1-Codex costs $1.25 per 1M input tokens and $10 per 1M output tokens through the API. A typical chat message costs about $7.50 per 1,000 messages.
What is the context window of GPT-5.1-Codex?
GPT-5.1-Codex accepts up to 400K tokens of input and can write up to 128K tokens in a single response.
What is the best alternative to GPT-5.1-Codex?
GPT-5.2 from OpenAI is a strong alternative. It offers: higher intelligence score, accepts file, newer release.
Can I use GPT-5.1-Codex alongside other models?
Yes. Shortcut Chat sends one prompt to GPT-5.1-Codex and any other models you pick at the same time, so you can compare answers side by side.
Try GPT-5.1-Codex next to every other model.
Use GPT-5.1-Codex alongside all the other models. Use one at a time, or multiple together. Get the best answer from every AI.