How much does GPT-5.1 cost per month?

For a chatbot handling 10,000 requests a day with 1,000 input and 500 output tokens each, GPT-5.1 costs about $1,875 per month at the provider's official prices (verified) ($1.25 per 1M input tokens, $10.00 per 1M output tokens).

Does GPT-5.1 support prompt caching?

Yes. Cached input costs $0.125 per 1M tokens, compared with $1.25 for regular input.

How long is GPT-5.1's context window?

GPT-5.1 accepts up to 400,000 tokens (400K) of context and returns up to 128,000 tokens per response.

Does GPT-5.1 have a batch price?

Yes. Asynchronous batch requests cost $0.625 per 1M input tokens and $5.00 per 1M output tokens.

GPT-5.1 API Pricing

OpenAI · released Nov 13, 2025 · 400K context · API model ID gpt-5.1

GPT-5.1 by OpenAI API pricing: $1.25 per 1M input tokens and $10.00 per 1M output tokens (verified against the official pricing page, Oct 9, 2026).

Prices

GPT-5.1 prices, USD per 1M tokens
Price	USD per 1M tokens
Input	$1.25
Output	$10.00
Cache read	$0.125
Cache write	Not published
Batch input	$0.625
Batch output	$5.00

Verified against the provider's official pricing page on Oct 9, 2026. Official pricing page

Estimated monthly cost

$1,875

per month

per day: $62.50
per request: $0.00625

Cost = input tokens × input price + output tokens × output price, 30 days a month. Cached input uses the cache read price. Cache write fees are not included.

Compare this workload across models

Monthly cost by workload

Workload	Per month
Chatbot1,000 in / 500 out tokens, 10,000 requests a day	$1,875/mo
RAG8,000 in / 500 out tokens, 5,000 requests a day	$2,250/mo
Coding agent50,000 in / 2,000 out tokens, 1,000 requests a day, 80% cached input	$1,125/mo

Context and capabilities

Context: 400,000 tokens
Max output: 128,000 tokens
Input: text, image
Output: text
Knowledge cutoff: Sep 30, 2024
Open weights: No
Tool calling: Yes
Reasoning: Yes
Structured outputs: Yes

Capabilities and limits as listed by models.dev.

Similarly priced models

Qwen3.8 Max · $2.00 in / $6.00 out
Mistral Medium 3.5 · $1.50 in / $7.50 out
Grok 4.7 · $2.00 in / $6.00 out
Claude Sonnet 5.5 · $2.00 in / $10.00 out

Price history

No price changes since we started tracking on Oct 8, 2026.

Questions

How much does GPT-5.1 cost per month?: For a chatbot handling 10,000 requests a day with 1,000 input and 500 output tokens each, GPT-5.1 costs about $1,875 per month at the provider's official prices (verified) ($1.25 per 1M input tokens, $10.00 per 1M output tokens).
Does GPT-5.1 support prompt caching?: Yes. Cached input costs $0.125 per 1M tokens, compared with $1.25 for regular input.
How long is GPT-5.1's context window?: GPT-5.1 accepts up to 400,000 tokens (400K) of context and returns up to 128,000 tokens per response.
Does GPT-5.1 have a batch price?: Yes. Asynchronous batch requests cost $0.625 per 1M input tokens and $5.00 per 1M output tokens.