GPT 5.1 Codex Max API pricing
Azure OpenAI · chat model · 272K context · ranked #1324 of 1809 by input price
What GPT 5.1 Codex Max costs in practice
GPT 5.1 Codex Max is priced at $1.25 per million input tokens and $10 per million output tokens , with cached input billed at $0.125 per million — roughly 90% cheaper than fresh input, which matters if your app resends a large system prompt. Against the median priced chat model ($0.5/1M in), this sits at 2.5×.
Monthly cost examples
Assuming 1,200 prompt + 400 completion tokens per request unless noted, billed 30 days a month and without cache hits.
| Workload | Cost / month | Cost / day |
|---|---|---|
| 1,000 requests/day | $165 | $5.5 |
| 10,000 requests/day | $1650 | $55 |
| 100,000 requests/day | $16500 | $550 |
| 1M summaries/month | $12999.87 | $433.33 |
Model a different profile in the cost calculator.
Capabilities
Provider description
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...
Cheaper alternatives
Ranked by blended cost (3× input + 1× output) — cheaper, but check context and capabilities before switching.
| # | Model | Provider | Input $/1M | Output $/1M | Cached $/1M | Context |
|---|---|---|---|---|---|---|
| 1 | Gemini Exp 1114 | Google Gemini | free | free | — | 1.0M |
| 2 | Gemini Exp 1206 | Google Gemini | free | free | — | 2.1M |
| 3 | Gemma 3 27b It | Google Gemini | free | free | — | 131K |
| 4 | Gemma 4 26b A4b It | Google Gemini | free | free | — | 262K |
| 5 | Gemma 4 31b It | Google Gemini | free | free | — | 262K |
| 6 | Learnlm 1.5 Pro Experimental | Google Gemini | free | free | — | 33K |
Data provenance
This page is assembled from the sources below. Where two sources disagree, both are shown.
- Our input price: $1.25
- Second source: —
- Our output price: $10
- Second source: —
More from Azure OpenAI
Frequently asked
› How much does GPT 5.1 Codex Max cost per 1,000 tokens?
About $0.00125 for input and $0.01 for output tokens, based on the per-million rates on this page.
› Is GPT 5.1 Codex Max cheaper than other models?
By input price it ranks #1324 of 1809 priced chat models in this index, putting it in the more expensive half of the market.
› How often is GPT 5.1 Codex Max's price checked?
The dataset was last refreshed 2026-09-13 13:40 UTC. Providers can change pricing at any time — verify with Azure OpenAI before committing to a budget.