GPT-5.1-Codex pricing & benchmarks
Released Nov 13, 2025 · served by 2 providers
What GPT-5.1-Codex is
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
- Model ID:
openai/gpt-5.1-codex - Modality: text+image->text
- Tool calling: supported · Structured output: supported
Providers and prices for GPT-5.1-Codex
The same model costs different amounts depending on who serves it. Prices are per 1M tokens, cheapest first. Uptime and throughput are OpenRouter's rolling measurements, not vendor claims.
| Provider | Input | Output | Context | Quant | Uptime 24h | Throughput |
|---|---|---|---|---|---|---|
| Azurecheapest | $1.25 | $10.00 | 400K | — | 100.0% | — |
| OpenAI | $2.50 | $20.00 | 400K | — | 0.0% | — |
GPT-5.1-Codex benchmark results
Design Arena head-to-head results, as reported through the OpenRouter model API.
| Category | Arena | Rank | Elo | Win rate |
|---|---|---|---|---|
| mobileapps | agents | #17 | 1199 | 53.4% |
| fullstack | agents | #26 | 1086 | 44.5% |
| webapps | agents | #33 | 1073 | 44.1% |
| dataviz | models | #47 | 1202 | 50.7% |
| gamedev | models | #53 | 1195 | 52.3% |
| codecategories | models | #60 | 1181 | 55.2% |
| website | models | #62 | 1186 | 56% |
FAQ
How much does the GPT-5.1-Codex API cost?
$1.25 per 1M input tokens and $10.00 per 1M output tokens. A typical workload of 1M input + 300K output tokens costs about $4.25.
Is GPT-5.1-Codex free?
No. It is a paid model starting at $1.25 per 1M input tokens, though some providers offer trial credits.
Which provider is cheapest for GPT-5.1-Codex?
Azure at $1.25 input / $10.00 output per 1M tokens.
Can I self-host GPT-5.1-Codex?
No. GPT-5.1-Codex is closed-weight and only available through hosted APIs.