GPT-5.1 API pricing
Standard tier, blended at 3:1 input to output: $3.44 per million tokens.
OpenAI charges $1.25 per million input tokens and $10.00 per million output tokens for GPT-5.1. It is sold in 5 forms, from $1.72 to $3.44 blended; the table below shows what each costs against standard. 2 of the models nearest it in price are cheaper on a blended basis.
Every tier of GPT-5.1
Blended at 3:1 input to output. The last column compares each against the standard tier.
| Source | ||||||||
|---|---|---|---|---|---|---|---|---|
| Standard Standard | gpt-5.1 | OpenAI | $1.25 | $10.00 | $0.125 | $3.44 | Standard | ↗ |
| Standard | gpt-5.1 | OpenRouter | $1.25 | $10.00 | $0.125 | $3.44 | Same | ↗ |
| Dated snapshot | gpt-5.1-2025-11-13 | OpenAI | $1.25 | $10.00 | $0.125 | $3.44 | Same | ↗ |
| Alias · Chat | gpt-5.1-chat-latest | OpenAI | $1.25 | $10.00 | $0.125 | $3.44 | Same | ↗ |
| Batch | gpt-5.1:batch | OpenRouter | $0.625 | $5.00 | $0.063 | $1.72 | −50% | ↗ |
Prices last checked: . Methodology
Which tier to use
What each costs against standard in our data, and the job it is for.
Batch
The batch tier (gpt-5.1:batch) is 50% cheaper than standard. Batch requests are queued and answered asynchronously, typically within 24 hours, so it suits work nobody is waiting on: evaluations, back-fills, bulk classification and tagging. Anything a user is waiting on belongs on the standard tier.
Chat variant
The vendor also lists a chat variant of gpt-5.1, listed at the same price as standard. It is the same model tuned or wired for one job, so pick one only when that is your job; otherwise standard is the reference price.
Dated snapshots
One dated snapshot (gpt-5.1-2025-11-13) is listed at the same price as standard. A snapshot pins the model to one release, while the undated name moves to newer releases when the vendor updates it. Pin a snapshot in production when your prompts depend on exact output; use the undated name to pick up improvements automatically.
Aliases
"-latest" names point at whichever release the vendor currently serves, listed at the same price as standard. The price can change under you when the alias moves, so budget against a pinned name.
Direct or through a reseller
Through OpenRouter, gpt-5.1 is the same price as buying direct. A reseller is worth it for one bill across vendors and automatic fallback; buy direct for the vendor's own batch, caching and rate-limit terms.
Against the models nearest in price
Standard tiers, blended at a 3:1 input to output ratio.
| Source | ||||||
|---|---|---|---|---|---|---|
| GPT-5.1 This model | OpenAI | $1.25 | $10.00 | 272,000 | $3.44 | ↗ |
| GPT-5 | OpenAI | $1.25 | $10.00 | 272,000 | $3.44 | ↗ |
| Gemini 2.5 Pro | Google AI | $1.25 | $10.00 | 1,048,576 | $3.44 | ↗ |
| GPT-5.1 Codex | OpenRouter | $1.25 | $10.00 | 400,000 | $3.44 | ↗ |
| GPT-4.1 | OpenAI | $2.00 | $8.00 | 1,047,576 | $3.50 | ↗ |
| o3 | OpenAI | $2.00 | $8.00 | 200,000 | $3.50 | ↗ |
| Llama 3.1 405B Instruct | Together AI | $3.50 | $3.50 | 4,096 | $3.50 | ↗ |
| Mistral Large | OpenRouter | $2.00 | $6.00 | 128,000 | $3.00 | ↗ |
| Grok 4.5 | xAI | $2.00 | $6.00 | 500,000 | $3.00 | ↗ |
Prices last checked: . Methodology
Questions
How much does GPT-5.1 cost per million tokens?
$1.25 per million input tokens and $10.00 per million output tokens, with cached input at $0.125. At a 3:1 input to output mix that blends to $3.44. Checked 28 Oct 2026.
How much cheaper is GPT-5.1 through the Batch API?
gpt-5.1:batch costs $0.625 in and $5.00 out per million tokens, 50% cheaper than standard, in exchange for asynchronous delivery.
What would GPT-5.1 cost for a real workload?
A thousand requests a day at 2,000 input and 600 output tokens each comes to $255.00 a month on the standard tier, or $127.50 through batch.
What is the context window for GPT-5.1?
272,000 tokens of input, with up to 128,000 tokens of output.
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