How much does GPT-5.1 cost?

GPT-5.1 costs $1.25 per million input tokens and $10 per million output tokens on standard pricing; other tiers (Standard, Batch, Flex) are also available. A workload of 20M input and 5M output tokens a month is about $75.

What is the context length of GPT-5.1?

GPT-5.1 accepts up to 400,000 tokens (400K) of input and can return up to 128,000 tokens in one response.

Does GPT-5.1 support tool calling and structured outputs?

Yes, GPT-5.1 supports function/tool calling and structured (JSON) outputs. Supported tools: Function calling, Structured outputs, JSON mode, Reasoning, Deterministic seed, Prompt caching.

What inputs and outputs does GPT-5.1 support?

GPT-5.1 accepts Image, Text, PDF as input and produces Text as output.

Which providers serve GPT-5.1?

GPT-5.1 is available from 5 API providers: OpenAI, Azure, OpenAI, Azure, OpenAI. Prices can differ by provider.

When was GPT-5.1 released?

GPT-5.1 was released by OpenAI in 2025-11.

GPT-5.1

gpt-5.1

API Provider site

GPT-5.1 reasoning model with adaptive thinking time. Built by OpenAI.

Prices updated recently

Input price

$1.25

per 1M tokens · Standard

Output price

$10

per 1M tokens · Standard

Input limit

400K

tokens

Output limit

128K

tokens

Input formats

TextImageVideoAudioPDF

Output formats

TextImageVideoAudioPDF

Compare

GPT-5.1 price history

2 price records since 9/25/2026

GPT-5.1 cost calculator

Input20M tokens

Output5M tokens

$75/month

Standard pricing

Overview

What is GPT-5.1?

GPT-5.1 is a text & reasoning and code & slms and vision model from OpenAI. GPT-5.1 reasoning model with adaptive thinking time. Its 400K context window and $1.25 input price make it a candidate for quality-focused production applications.

Code generationAgent workflowsImage understandingDocument analysis

Benchmarks

GPT-5.1 benchmarks & speed

How GPT-5.1 scores on standardized evaluations, and where it lands among every model we track.

24.7

Intelligence Index

Better than 62% of 153 models

136tok/s

Output speed

Better than 71% of 119 models

Reasoning

GPQA Diamond

87.3%

Graduate-level scientific reasoning · top 35%

HLE

28.5%

Humanity's Last Exam · top 38%

Latency & design

Time to first token: 20.38s

Independent scores from Artificial Analysis and DesignArena · updated 10/5/2026. Higher is better; ranks compare against every model we track with that score.

Rates

GPT-5.1 pricing

Pricing is based on token usage. Provider-specific caching, batch, regional, and tool charges may affect the final cost.

Input · Standard

$1.25

Per 1M tokens

Cached input · Standard

$0.13

Per 1M tokens

Capabilities

GPT-5.1 Tools

Tools available when using GPT-5.1 through supported provider APIs.

Function calling

Supported

Structured outputs

Supported

JSON mode

Supported

Reasoning

Supported

Built-in web search

Not supported

Log probabilities

Not supported

Deterministic seed

Supported

Parallel tool calls

Not supported

Prompt caching

Supported

Where to run it

GPT-5.1 API providers

5 providers serve GPT-5.1. Prices are per 1M tokens; uptime is the last 24 hours.

Provider	Input	Output	Cached	Context	Uptime
OpenAI	$0.63	$5.00	$0.06	400K	100%
Azure	$1.25	$10	$0.13	400K	99.96%
OpenAI	$1.25	$10	$0.13	400K	99.99%
Azure	$1.38	$11	$0.14	400K	100%
OpenAI	$2.50	$20	$0.25	400K	—

OpenAI

Input: $0.63
Output: $5.00
Cached: $0.06
Context: 400K
Uptime: 100%

Azure

Input: $1.25
Output: $10
Cached: $0.13
Context: 400K
Uptime: 99.96%

OpenAI

Input: $1.25
Output: $10
Cached: $0.13
Context: 400K
Uptime: 99.99%

Azure

Input: $1.38
Output: $11
Cached: $0.14
Context: 400K
Uptime: 100%

OpenAI

Input: $2.50
Output: $20
Cached: $0.25
Context: 400K
Uptime: —

Strengths and limitations

Strengths

Measured results (AA Intelligence 24.7 · Arena Elo 1228 · MMLU-Pro 78.2%) position it for demanding production work.
400K context supports large documents, repositories and extended conversations.
Supports text & reasoning and code & slms and vision workloads in one model.

Limitations

Generated tokens cost 8× more than input tokens, which matters for verbose responses.
Large context capacity does not guarantee consistent retrieval across the entire prompt.
Arena Elo and MMLU-Pro are directional; test accuracy, latency and reliability on your own workload before committing.

Arena Elo, MMLU-Pro and pricing figures are illustrative; validate current vendor terms before purchase.

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Frequently asked questions about GPT-5.1

GPT-5.1 is a text & reasoning and code & slms and vision model from OpenAI. GPT-5.1 reasoning model with adaptive thinking time.