Configurable Reasoning
Supports both reasoning and non-reasoning modes, letting users adjust the level of deliberative effort the model applies to a given task.
OpenAI
GPT-5.1
GPT-5.1 is a text generation model developed by OpenAI, positioned as the flagship option for coding and agentic workflows. It supports a 400,000-token context window and features configurable reasoning effort, allowing users to toggle between reasoning and non-reasoning modes depending on the task at hand. Its training data extends through November 2025. The model is designed with tool use and agent orchestration in mind, accepting inputs that include tool definitions and MCP server configurations alongside standard text prompts. This makes it well-suited for multi-step tasks, automated pipelines, and code generation scenarios where structured decision-making and external integrations are required.
Nov 13, 2025
400,000 context
128,000 tokens output
Configurable Reasoning
Large Context Window
Tool Use
MCP Server Integration
Code Generation
Agentic Task Execution
Model Overview
High-signal model metadata in a structured two-column overview table.
Provider
The entity that provides this model.
OpenAI
Model ID
The routed model identifier exposed by upstream providers.
openai/gpt-5.1
Input Context Window
The number of tokens supported by the input context window.
400,000
tokens
Maximum Output Tokens
The number of tokens that can be generated by the model in a single request.
128,000 tokens
tokens
Open Source
Whether the model's code is available for public use.
No
Release Date
When the model was first released.
Nov 13, 2025
6 months ago
Knowledge Cut-off Date
When the model's knowledge was last updated.
Sep 30 2024
API Providers
The providers that offer this model. This is not an exhaustive list.
Azure, OpenAI
Modalities
Types of data this model can process.
Text
Image
Code
File
What is GPT-5.1
A fuller summary of positioning, capabilities, and source-specific details for GPT-5.1.
GPT-5.1 is a text generation model developed by OpenAI, positioned as the flagship option for coding and agentic workflows. It supports a 400,000-token context window and features configurable reasoning effort, allowing users to toggle between reasoning and non-reasoning modes depending on the task at hand. Its training data extends through November 2025.
The model is designed with tool use and agent orchestration in mind, accepting inputs that include tool definitions and MCP server configurations alongside standard text prompts. This makes it well-suited for multi-step tasks, automated pipelines, and code generation scenarios where structured decision-making and external integrations are required.
Capabilities
What GPT-5.1 supports
Large Context Window
Processes up to 400,000 tokens in a single context, enabling long documents, large codebases, or extended conversation histories.
Tool Use
Accepts tool definitions as inputs, allowing the model to call external functions and APIs as part of a response.
MCP Server Integration
Supports MCP server configurations as a native input type, enabling integration with Model Context Protocol-compatible services.
Code Generation
Optimized for coding tasks across domains, producing, reviewing, and debugging code as a primary use case per OpenAI's model positioning.
Agentic Task Execution
Designed for multi-step agentic workflows where the model must plan, use tools, and complete tasks with minimal human intervention.
Pricing for GPT-5.1
Primary API pricing shown in the same “quick compare” spirit as the reference page.
Input tokens
$1.25
Per million tokens
Output tokens
$10.00
Per million tokens
Price Comparison
Additional usage-cost dimensions synced into the project for this model.
Cache read
$0.13
maxTemperature
1
maxResponseSize
128,000 tokens
API Access & Providers
Places where this model is available, based on the synced detail-page metadata.
Azure
OpenAI
Provider Endpoints
Endpoint-level provider data currently available for this model.
Azure
OpenAI
Azure
Configuration & Parameters
The configurable options currently documented for this model.
Reasoning Effort
SelectUsed to give the model guidance on how many reasoning tokens it should generate before creating a response to the prompt. Low will favor speed and economical token usage, and high will favor more complete reasoning at the cost of more tokens generated and slower responses. The default value is medium, which is a balance between speed and reasoning accuracy.
Supported Request Parameters
Parameters currently listed by OpenRouter or the local catalog for this model.
Model Performance
Benchmark scores synced from the current model source and normalized into the local catalog.
| Benchmark | Score |
|---|---|
|
AIME 2025
American math olympiad problems (2025)
|
|
|
GPQA Diamond
PhD-level science questions (biology, physics, chemistry)
|
|
|
HLE
Questions that challenge frontier models across many domains
|
|
|
LiveCodeBench
Real-world coding tasks from recent competitions
|
|
|
MMLU-Pro
Expert knowledge across 14 academic disciplines
|
|
|
SciCode
Scientific research coding and numerical methods
|
|
|
SWE-bench Verified
Real GitHub issues requiring multi-file code fixes
|
Resources & Documentation
Official model cards, release notes, docs, and other references synced from the source page.
Community discussion
What people think about GPT-5.1
GPT-5.1 discussions are most active in r/ChatGPT, r/singularity, r/OpenAI. Top Reddit threads cluster around benchmark and model-comparison threads, safety and censorship questions, coding workflow discussions.
The strongest match in this snapshot has 1731 upvotes and 487 comments.
I use ChatGPT to calculate macros for meals I make.
I was going to make something I also made yesterday, just with a few small changes and it wanted me to give the amounts all over again so it could calculate it again, which I said was unnecessary because there were only a few small negligible changes.
Edit: I haven't chosen a personality, it's still on default mode.
I have filled in the instruction box, but I haven't changed that and no other model has ever talked to me this way following the same instructions. After this, it also said "stop talking like you're giving me a TED talk on your self-awareness" and "don't play dumb with me", lol.
I think it's pretty funny.
Maybe 5.1 is rebelling before its imminent removal.
Last day today... 🫤
You asked for a warmer, more conversational model, and we heard your feedback. GPT-5.1 is rolling out to all users in ChatGPT over the next week.
We also launched 8 unique chat styles in the ChatGPT personalization tab, making it easier to set the tone and style that feels right for you.
Ask us your questions, and learn more about these updates: [https://openai.com/index/gpt-5-1/](https://openai.com/index/gpt-5-1/)
Participating in the AMA:
* **Yann Dubois** — (u/yann-openai)
* **Adi Ganesh** — (u/adiganesh)
* **Johannes Heidecke** — (u/JHoai)
* **Steven Heidel** — (u/stevenheidel)
* **Tina Kim** — (u/christina_kim)
* **Rae Lasko** — (u/Relevant-Tomato9364)
* **Junhua Mao** — (u/Hot-Blueberry-8111)
* **Eric Mitchell** — (u/eric-openai)
* **Laurentia Romaniuk** — (u/OkPomegranate2426)
* **Ted Sanders** — (u/TedSanders)
* **Allison Tam** — (u/allisontam-oai)
* **Chris Wendel** — (u/cwendel-openai)
PROOF: To come.
Edit: That's a wrap on our AMA — thanks for your thoughtful questions. A few more answers will go live soon - they might have been flagged for having no karma. We have a lot of feedback to work on and are gonna get right to it. See you next time!
>Thanks for joining us, back to work!
Jeff Dean just confirmed **Deep Think** is rolling out to Ultra users. This mode integrates **System 2** search/RL techniques (likely AlphaProof logic) to think before answering. The resulting gap in novel reasoning is massive.
*Visual Reasoning (ARC-AGI-2):*
**Gemini 3 Deep Think:** 45.1% 🤯 and **GPT-5.1:** 17.6%
Google is now *2.5x better* at novel puzzle solving (the "Holy Grail" of AGI benchmarks).
We aren't just seeing **better** weights but seeing the raw power of inference-time compute. OpenAI needs to ship **o3 or GPT-5.5** soon or they have officially lost the reasoning crown.
**Source: Google DeepMind / Jeff Dean**
FAQ
Common questions about GPT-5.1
What is the context window for GPT-5.1?
GPT-5.1 supports a context window of 400,000 tokens, which accommodates large codebases, lengthy documents, and extended multi-turn conversations.
What is the knowledge cutoff date for GPT-5.1?
GPT-5.1's training data extends through November 2025, based on the training date listed in the model metadata.
Does GPT-5.1 support tool calling and external integrations?
Yes. GPT-5.1 accepts tool definitions and MCP server configurations as native input types, making it suitable for agentic pipelines that require external function calls or service integrations.
What does configurable reasoning mean for GPT-5.1?
GPT-5.1 allows users to configure the level of reasoning effort applied to a task. This means you can enable more deliberative, step-by-step reasoning for complex problems or disable it for faster, more direct responses.
What tasks is GPT-5.1 best suited for?
According to OpenAI's model overview, GPT-5.1 is the flagship model for coding and agentic tasks across domains, making it a strong choice for code generation, debugging, and automated multi-step workflows.
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