OpenAI

o1

OpenAI o1 is a large language model developed by OpenAI and trained using reinforcement learning to perform complex, multi-step reasoning. Unlike standard language models that respond immediately, o1 generates an internal chain of thought before producing its final answer, allowing it to work through difficult problems more systematically. It supports a 200,000-token context window, tool use, and Structured Outputs via the API. The model is designed for tasks in coding, mathematics, and science where careful reasoning is more important than broad general knowledge. It has demonstrated notable benchmark results, including ranking in the 89th percentile on Codeforces competitive programming questions, placing among the top 500 students in the US on the AIME math qualifier, and exceeding human PhD-level accuracy on the GPQA benchmark covering physics, biology, and chemistry. It is well-suited for developers and researchers who need a model that can handle technically demanding problems within a large context.

Dec 17, 2024 200,000 context 100,000 tokens output
Chain-of-Thought Reasoning Large Context Window Structured Outputs Tool Use Math & Science Tasks Code Generation

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/o1

Input Context Window

The number of tokens supported by the input context window.

200,000 tokens

Maximum Output Tokens

The number of tokens that can be generated by the model in a single request.

100,000 tokens tokens

Open Source

Whether the model's code is available for public use.

No

Release Date

When the model was first released.

Dec 17, 2024 1 year ago

Knowledge Cut-off Date

When the model's knowledge was last updated.

2023

API Providers

The providers that offer this model. This is not an exhaustive list.

OpenAI

Modalities

Types of data this model can process.

Text Image Code File

What is o1

A fuller summary of positioning, capabilities, and source-specific details for o1.

OpenAI o1 is a large language model developed by OpenAI and trained using reinforcement learning to perform complex, multi-step reasoning. Unlike standard language models that respond immediately, o1 generates an internal chain of thought before producing its final answer, allowing it to work through difficult problems more systematically. It supports a 200,000-token context window, tool use, and Structured Outputs via the API.

The model is designed for tasks in coding, mathematics, and science where careful reasoning is more important than broad general knowledge. It has demonstrated notable benchmark results, including ranking in the 89th percentile on Codeforces competitive programming questions, placing among the top 500 students in the US on the AIME math qualifier, and exceeding human PhD-level accuracy on the GPQA benchmark covering physics, biology, and chemistry. It is well-suited for developers and researchers who need a model that can handle technically demanding problems within a large context.

Capabilities

What o1 supports

RN

Chain-of-Thought Reasoning

Generates an internal chain of thought before responding, enabling systematic problem-solving across multi-step tasks. This reasoning process is produced automatically before each output.

CTX

Large Context Window

Supports up to 200,000 tokens of context, allowing long documents, codebases, or conversation histories to be processed in a single request.

JSON

Structured Outputs

Returns responses conforming to a specified JSON schema, making it straightforward to integrate model outputs into downstream applications.

TL

Tool Use

Supports function calling and external tool integration, enabling the model to invoke developer-defined tools during a reasoning session.

AI

Math & Science Tasks

Optimized for quantitative and scientific reasoning, with benchmark results including top-500 placement on the AIME qualifier and PhD-level accuracy on GPQA.

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Code Generation

Handles complex programming tasks with documented performance at the 89th percentile on Codeforces competitive programming questions.

Pricing for o1

Primary API pricing shown in the same “quick compare” spirit as the reference page.

Price Comparison

Additional usage-cost dimensions synced into the project for this model.

Cache read $7.50
maxTemperature 2
maxResponseSize 100,000 tokens

API Access & Providers

Places where this model is available, based on the synced detail-page metadata.

OpenAI

Provider Endpoints

Endpoint-level provider data currently available for this model.

OpenAI

Max output: 100,000 1d uptime: 100.0% Supported params: 8 Implicit caching: No

Configuration & Parameters

The configurable options currently documented for this model.

Reasoning Effort

Select

Used 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.

Default: medium
Low Medium High

Supported Request Parameters

Parameters currently listed by OpenRouter or the local catalog for this model.

Reasoning Effort

Model Performance

Benchmark scores synced from the current model source and normalized into the local catalog.

Benchmark Score
AIME 2024
American math olympiad problems
72.3%
GPQA Diamond
PhD-level science questions (biology, physics, chemistry)
74.7%
HLE
Questions that challenge frontier models across many domains
7.7%
LiveCodeBench
Real-world coding tasks from recent competitions
67.9%
MATH-500
Undergraduate and competition-level math problems
97.0%
MMLU-Pro
Expert knowledge across 14 academic disciplines
84.1%
SciCode
Scientific research coding and numerical methods
35.8%

Resources & Documentation

Official model cards, release notes, docs, and other references synced from the source page.

Community discussion

What people think about o1

o1 discussions are most active in r/singularity, r/ChatGPT, r/OpenAI. Top Reddit threads cluster around benchmark and model-comparison threads, coding workflow discussions.

The strongest match in this snapshot has 10759 upvotes and 138 comments.

r/pourover 3 upvotes 2 comments February 27, 2026
O1 recipe

What’s your go-to recipe for the OREA O1?

I’d also love to know your grinder settings (Fellow Ode Gen 1).

Open Reddit thread
r/StableDiffusion 450 upvotes 147 comments May 9, 2026
HiDream-O1-Image - A pixel space model , no need for VAE, , 8B parameters.

Model
[https://huggingface.co/HiDream-ai/HiDream-O1-Image-Dev](https://huggingface.co/HiDream-ai/HiDream-O1-Image-Dev)
[https://huggingface.co/HiDream-ai/HiDream-O1-Image](https://huggingface.co/HiDream-ai/HiDream-O1-Image)

HiDream-O1-Image for 50 steps
HiDream-O1-Image-Dev for 28 steps

HiDream-O1-Image is a natively unified image generative foundation model built on a Pixel-level Unified Transformer (UiT) without external VAEs or disjoint text encoders, which natively encodes raw pixels, text, and task-specific conditions in a single shared token space — supporting text-to-image, image editing, and subject-driven personalization at up to 2,048 × 2,048.

Key Features

* **Pixel-Level Unified Transformer** — One end-to-end model on raw pixels, no VAE, no disjoint text encoder.
* **One Model, Many Tasks** — Text-to-image, long-text rendering, instruction editing, subject-driven personalization, and storyboard generation in a single architecture.
* **Reasoning-Driven Prompt Agent** — Built-in "thinking" agent that resolves implicit knowledge, layout, and text rendering before generation.
* **Native High Resolution** — Direct synthesis up to 2,048 × 2,048 with sharp fine-grained detail.
* **Exceptional Efficiency and Versatility at 8B Scale** — With only 8B parameters, achieves performance parity with or even surpasses larger open-source DiTs and leading closed-source models.

Open Reddit thread
r/VisaSuccess 16 upvotes 15 comments March 6, 2026
O1 visa approved after months of preparation

My O1 visa was approved recently and it honestly feels like a big milestone after months of preparation. Putting the petition together took quite a bit of time because of the recommendation letters, supporting documents and organizing everything in a way that clearly showed my work in the field.

When the interview day finally came, it was actually calmer than I expected, the conversation was fairly brief and focused on the petition and the purpose of the visa. It thankfully got approved after a very stressful time just thoguht of sharing it here.

Open Reddit thread
r/immigration 21 comments March 4, 2025
O1 denied

O1 visa petition approved online by USCIS then went to embassy for stamp and officer denied and gave us 214b letter saying cant appeal.

Open Reddit thread
r/immigration 34 comments July 29, 2025
O1 visa advice - Feeling terrified

Now guys, I get it. You probably get asked this question **A THOUSAND TIMES** a day. But hear me out.

So I did it, I took the first step towards staying in the US. I got both my B.S. and my M.S. in the States (Florida). I was working CPT before my graduation for around 2 years, then became a Founding Data Scientist of a Startup alongside a UCLA and Stanford professor for OPT (at the time I was also an online course instructor for an AI course), and then got a job as an AI Data Scientist for a big corporation.

I do not, however, have any publications out there, I just have 1 conference talk.

Now, I get it, this is pretty bad considering O1, and that I should follow the H1B path. The thing is... H1B is a lottery, and even if I excel at my job I still might not get in. I talked with my old boss (Stanford & UCLA professor) and he wants me to join the research team at his startup to publish papers alongside them. He really cares for me, and wants to see me staying in the country.

Aside from that, my recommendations would probably be my next best strength. I can pull out 9/10 **REALLY GOOD ONES** by leaders in the industry I work in.

In any case, I have less than 2 years left on my OPT (started this late January). What can I do in... say the next year to build my case even more?

Open Reddit thread
View more discussions →
FAQ

Common questions about o1

What is the context window for o1?

The o1 model supports a context window of 200,000 tokens, allowing large volumes of text, code, or documents to be included in a single request.

What is the training data cutoff for o1?

Based on the available metadata, o1's training data has a cutoff of late 2023.

What types of tasks is o1 best suited for?

o1 is optimized for coding, mathematics, and science tasks that require complex, multi-step reasoning. It is particularly useful when the problem demands careful logical analysis rather than broad general knowledge.

Does o1 support tool use and structured outputs?

Yes. o1 supports both tool use (function calling) and Structured Outputs, which allows responses to conform to a developer-specified JSON schema.

How does o1 differ from standard OpenAI text generation models?

o1 is trained with reinforcement learning specifically to reason before responding. It produces an internal chain of thought prior to generating its final answer, which is distinct from models that respond without an explicit intermediate reasoning step.

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