openai
OpenAI: GPT-5.1-Codex API Pricing
OpenAI: GPT-5.1-Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens (cache reads: $0.130). Context window: 400K. Prices verified 2026-08-23 Β· source
Input / 1M tokens
$1.25
Output / 1M tokens
$10.00
Context window
400K
Max output
128K
What would OpenAI: GPT-5.1-Codex cost you per month?
| Workload | Requests/mo | Avg tokens (in/out) | Est. monthly cost |
|---|---|---|---|
| Light chatbot | 10,000 | 800 / 400 | $50.00 |
| Coding agent | 5,000 | 8,000 / 2,000 | $150.00 |
| RAG pipeline | 30,000 | 4,000 / 500 | $300.00 |
| Doc summarizer | 2,000 | 20,000 / 1,000 | $70.00 |
Estimates use list prices without prompt caching. Caching can cut input cost by up to 90% on repeated context.
About OpenAI: GPT-5.1-Codex
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....
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Official resources
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