GPT-5.1-Codex-Max
by OpenAI · openai/gpt-5.1-codex-max · #250 cheapest of 325 paid models
Prices updated Jul 22, 2026, 1:38 AM UTC · refreshed hourly
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...
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Pricing
Input
$1.25
per 1M tokens
Output
$10.00
per 1M tokens
Blended (3:1)
$3.44
3 input : 1 output
Cache read
$0.125
per 1M cached tokens
Cache write
—
per 1M tokens
Cache & batch economics
Effective prices for GPT-5.1-Codex-Max with prompt caching.
| Cache hit rate | Effective blended $/1M | Example request* | vs no cache |
|---|---|---|---|
| 0% | $3.44 | $0.1375 | — |
| 50% | $3.02 | $0.0813 | −41% |
| 90% | $2.68 | $0.0362 | −74% |
*Example: 100K sticky context + 2K new input + 1K output. Batch discount is an approximate 50% off list rates for this provider’s batch API. Confirm on the vendor’s pricing page.
What a request costs
| Workload | Input tokens | Output tokens | Cost / request | Cost / 1K requests |
|---|---|---|---|---|
| Short chat message | 500 | 300 | $0.003625 | $3.62 |
| Document summary | 8,000 | 1,000 | $0.02 | $20.00 |
| Codebase question (RAG) | 30,000 | 2,000 | $0.0575 | $57.50 |
| Long-context analysis | 150,000 | 5,000 | $0.2375 | $237.50 |
Specs
Context window
400K
tokens
Max output
128K
tokens
Input modalities
text, image
Tokenizer
GPT