openai
OpenAI: GPT-5.1 API Pricing
OpenAI: GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens (cache reads: $0.125). 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 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
GPT-5.1 is the latest frontier-grade model in the GPT-5 series, offering stronger general-purpose reasoning, improved instruction adherence, and a more natural conversational style compared to GPT-5. It uses adaptive reasoning...
Compare OpenAI: GPT-5.1 with
Official resources
- OpenAI: GPT-5.1 on OpenRouter β live endpoint, pricing source of record.
- Get an OpenRouter API key β β one key, every model including GPT-5.1. Free credits on signup.
- Shred your current bill β paste a CSV and see if switching saves money.