GPT-5.1 Codex
DeprecatedGPT-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 $10.00 / 1M output. A GPT-5.1 variant purpose-built for agentic coding tasks in Codex environments, available exclusively via the Responses API.
| Benchmarks | |
|---|---|
| Intelligence Index | #132 |
| Math Index | #10 |
| MMLU-Pro | #24 |
| GPQA | #88 |
| HLE | #116 |
| LiveCodeBench | #19 |
| IFBench | #67 |
| Time to First Token | #554 |
| SciCode | #169 |
| AIME 2025 | #10 |
| LCR | #156 |
| TerminalBench Hard | #73 |
| TAU2 | #108 |
| Output TPS | #91 |
Capabilities
Input3/5
Text✓
Image✓
Audio·
Video·
PDF✓
Output1/5
Text✓
Image·
Audio·
Video·
Embedding·
Capabilities7/13
Reasoning✓
Adaptive Reasoning·
Function Calling✓
Parallel Function Calling✓
Structured Outputs✓
Native JSON Schema✓
Web Search✓
URL Context·
Computer Use·
Code Execution·
File Search·
Prompt Caching✓
Assistant Prefill·
Pricing by Provider
US Dollar ($)
Per 1M tokens
| Provider | Standard | Fast | |||||
|---|---|---|---|---|---|---|---|
| Input $ / 1M | Output $ / 1M | Cache Read $ / 1M | Web Search $ / request | Input $ / 1M | Output $ / 1M | Cache Read $ / 1M | |
| $1.38 | $11.00 | $0.138 | N/A | N/A | N/A | N/A | |
| $1.25 | $10.00 | $0.125 | N/A | N/A | N/A | N/A | |
| — | — | — | — | $2.50 | $20.00 | $0.25 | |
| $1.25 | $10.00 | $0.125 | N/A | — | — | — | |
| $1.25 | $10.00 | $0.13 | $0.010 | — | — | — | |
| $1.25 | $10.00 | $0.13 | N/A | — | — | — | |
Cost Calculator
US Dollar ($)
Preset:
Versions
| Version | Released | Context | Input / 1M | Output / 1M | Status |
|---|---|---|---|---|---|
| GPT-6.1 Sol | 1.1M | $2.00 | $10.00 | Available | |
| GPT-6 Sol | 1.1M | $2.00 | $10.00 | Available | |
| GPT-6 Luna | 1.1M | $0.100 | $0.500 | Available | |
| GPT-6 Astra | 1.1M | $10.00 | $50.00 | Available | |
| GPT-5.6 Sol | 1.1M | $4.00 | $20.00 | Available | |
| GPT-5.6 Terra | 1.1M | $2.00 | $12.00 | Available | |
| GPT-5.6 Luna | 1.1M | $0.200 | $1.20 | Available | |
| GPT-5.5 | 1.1M | $5.00 | $30.00 | Available | |
| GPT-5.4 Mini | 400K | $0.750 | $4.50 | Available | |
| GPT-5.4 Nano | 400K | $0.200 | $1.25 | Deprecating | |
| GPT-5.1 Codex | 400K | $1.25 | $10.00 | Current |