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OpenAI: GPT-5.1 API Pricing

OpenAI: GPT-5.1 is an API model from openai. It costs $1.25 per 1M input tokens and $10 per 1M output tokens, with cached input at $0.125. Its context window is 400,000 tokens with up to 128,000 output tokens. A workload of 10M input + 2M output tokens costs about $32.5 per month. The official openai list price is $1.25 input / $10 output per 1M tokens, which matches the catalog price tracked here.
Input
$1.25
per 1M tokens
Output
$10
per 1M tokens
Cached input
$0.125
per 1M tokens
Context window
400K
400,000 tokens
Blended (80/20)
$3
per 1M tokens

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...

How much does OpenAI: GPT-5.1 cost for a real workload?

At 10M input + 2M output tokens per month, OpenAI: GPT-5.1 costs about $32.5 ($12.5 input + $20 output). Try your own volumes in the cost calculator.

What is the official OpenAI: GPT-5.1 price?

Official (openai)Catalog (OpenRouter)
Input /1M$1.25$1.25
Output /1M$10$10
Cached input /1M$0.125$0.125

✓ Matches the official list price. Source: openai official pricing page, checked 2026-10-21.

What are cheaper alternatives to OpenAI: GPT-5.1?

Where to run OpenAI: GPT-5.1

AI/ML API: one API key for 400+ models, including most models tracked here · Novita AI: pay-as-you-go APIs for open models (DeepSeek, Qwen, Llama and more) plus GPU cloud. Prices there follow each platform's own catalog and can differ from the list prices tracked here.

Run it on AI/ML API →Run it on Novita AI →

Disclosure: links to these platforms may be affiliate links — if you sign up or buy through them, LLMPrices may earn a commission at no extra cost to you.

Compare OpenAI: GPT-5.1 with other models

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Frequently asked questions

How much does OpenAI: GPT-5.1 cost?

OpenAI: GPT-5.1 costs $1.25 per 1M input tokens and $10 per 1M output tokens (list price, snapshot October 22, 2026). At 10M input + 2M output tokens per month that is about $32.5.

What is the context window of OpenAI: GPT-5.1?

OpenAI: GPT-5.1 has a context window of 400,000 tokens and can return up to 128,000 output tokens per response.

What are cheaper alternatives to OpenAI: GPT-5.1?

Cheaper models include Google: Gemini 3.5 Flash ($1.5 in / $9 out), Pareto 26.9 ($2.5 in / $7.5 out), OpenAI: o3 ($2 in / $8 out). See the full list on this page.

Is OpenAI: GPT-5.1 free to use?

No. OpenAI: GPT-5.1 is a paid model at $1.25 input / $10 output per 1M tokens. 21 free models are listed on the free models page.

What is the official price of OpenAI: GPT-5.1?

On openai's official pricing page (checked 2026-10-21), OpenAI: GPT-5.1 is listed at $1.25 per 1M input tokens and $10 per 1M output tokens. The catalog price tracked on this page matches it exactly.

Provider: openai · Model ID: openai/gpt-5.1 · Modality: text+image+file->text · Price snapshot October 22, 2026, refreshed daily. How we collect prices