What is OpenAI: GPT-5.1's context window?

OpenAI: GPT-5.1 supports a context window of 256,000 tokens, allowing you to process large documents and maintain long conversations.

How to use OpenAI: GPT-5.1 API via Ofox?

Simply set your base URL to https://api.ofox.run/v1 and use your Ofox API key. The API is OpenAI-compatible — just change the base URL and API key in your existing code.

OpenAI: GPT-5.1

Name: OpenAI: GPT-5.1
Brand: openai
Price: 1.25 USD
Availability: InStock
Rating: 5 (1 reviews)

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openai/gpt-5.1

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GPT-5.1 is OpenAI's enhanced GPT-5 release from 2025-11-13, bringing improved reasoning, better instruction following, and stronger coding performance. It handles vision, audio, and video input alongside reasoning, tool use (function calling), prompt caching, and web search. Context: 256K tokens, output: 128K — four times the output budget of GPT-5. Accessible via the OpenAI-compatible protocol through Ofox.

Context Window

256K

Max Output Tokens

128K

Released

2025-11-13

Capabilities

VisionFunction CallingReasoningPrompt CachingWeb SearchAudio InputVideo Input

Available Providers

Azure

Supported Protocols

openai

Providers

Azure

Input Tokens

$1.25/M

Output Tokens

$10/M

Cache Read

$0.13/M

Output Image

$32/M

Web Search

$0.035/R

Protocols

openai/v1/chat/completions/v1/responses

Code Examples

from openai import OpenAI

client = OpenAI(
    base_url="https://api.ofox.run/v1",
    api_key="YOUR_OFOX_API_KEY",
)

response = client.chat.completions.create(
    model="openai/gpt-5.1",
    messages=[
        {"role": "user", "content": "Hello!"}
    ],
)

print(response.choices[0].message.content)

Benchmarks

LMArena ↗Evaluated as gpt-5.1

OpenAI: GPT-5.1 scores 1439 in the Overall category of the LMArena text leaderboard (style control), ranking #67 of 374 models based on 43,424 human preference votes (updated 2026-07-12).

Benchmark scores for gpt-5.1 on LMArena
Category	95% CI	Rank	Votes
Overall	1435–1442	#67 of 374	43,424
Hard Prompts	1450–1460	#77 of 374	23,571
Coding	1467–1481	#84 of 369	9,121
Math	1412–1434	#90 of 362	2,864
Creative Writing	1402–1418	#64 of 372	6,428
Instruction Following	1421–1433	#71 of 374	11,850
Chinese	1464–1491	#69 of 344	2,028

Source: LMArena · CC BY 4.0 · Updated 2026-07-12 · Methodology ↗ · Ranks compare models within each category of the LMArena text leaderboard (style control). Scores come from third-party human preference evaluations, not from OFOX.