GPT-5.1 Codex
GPT-5.1 Codex is OpenAI's language model with a 400K context window and up to 128K output tokens, available from 4 providers, starting at $1.25 / 1M input and $10.00 / 1M output. A GPT-5.1 variant purpose-built for agentic coding tasks in Codex environments, available exclusively via the Responses API.
Capabilities
Input3/5
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Output1/5
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Capabilities7/13
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Pricing by Provider
| Provider | Standard | ||
|---|---|---|---|
| Input $ / 1M | Output $ / 1M | Cache Read $ / 1M | |
OpenAI | $1.25 | $10.00 | $0.125 |
 OpenRouter | $1.25 | $10.00 | $0.125 |
 Vercel AI Gateway | $1.25 | $10.00 | $0.125 |
 Azure AI Foundry | $1.38 | $11.00 | $0.140 |
Cost Calculator
Preset:
Compares every provider & tier in USD
Versions
| Version | Released | Context | Input / 1M | Output / 1M | Status |
|---|---|---|---|---|---|
| GPT-5.5 | 1.1M | $5.00 | $30.00 | Available | |
| GPT-5.4 Mini | 1.1M | $0.750 | $4.50 | Available | |
| GPT-5.4 Nano | 1.1M | $0.200 | $1.25 | Available | |
| GPT-5.4 | 1.1M | $2.50 | $15.00 | Available | |
| GPT-5.3 Codex | 400K | $1.75 | $14.00 | Available | |
| GPT-5.2 Codex | 400K | $1.75 | $14.00 | Available | |
| GPT-5.2 | 410K | $1.75 | $14.00 | Available | |
| GPT-5.1 Codex | 400K | $1.25 | $10.00 | Current | |
| GPT-5.1 | 410K | $1.25 | $10.00 | Available | |
| GPT-5.1 Codex Mini | 400K | $0.250 | $2.00 | Available | |
| GPT-5 Codex | 400K | $1.25 | $10.00 | Available |