o1

OpenAIopenai/o1Providers: 1
Inputi$15per 1M tokens
Outputi$60per 1M tokens
Contexti200K200,000 tokens
ReleasedDec 17, 2024Max output: 100K

Where it stands

Quality in independent tests against price, next to 135 other models. Up means more capable, left means cheaper.

100110120130140150160170$0.01$0.03$0.1$0.3$1$3$10$30$100Overall indexPrice per million tokens, log scale (3 parts input to 1 part output)↖ Cheaper and smartero1
Scores: Epoch AI (CC BY 4.0). Prices: OpenRouter. View as a table

About this model

o1 is an AI model from OpenAI, made available through the API on December 17, 2024. It can read up to 200,000 tokens in one request, roughly 375 pages of text, and write up to 100,000 tokens in a single answer. Besides text, it accepts images and files such as PDFs as input.

Through the API it costs $15 per million input tokens and $60 per million output tokens. It is among the more expensive models we track, a price usually reserved for the most capable, flagship-class models.

It supports extended reasoning: it can "think" step by step before answering, which helps on maths, code and complex questions. It can call tools and functions, so developers can connect it to search, databases or other software.

Quality scores

Rankings →
141.9Overall index · #89 of 136
  • GPQA DiamondVery hard multiple-choice questions in biology, physics and chemistry, written by PhD experts. Random guessing scores 25%.76.8%#72 of 116
  • AIME mathCompetition-level math problems in the style of the American Invitational Mathematics Examination. Share solved.73.3%#72 of 112
  • FrontierMathOriginal, unpublished math problems written by professional mathematicians, from advanced to research level. Share solved.14.7%#66 of 73
  • SimpleQA VerifiedShort factual questions. Measures how often the model gets facts right instead of making something up.41.1%#36 of 69

Benchmark data: Epoch AI, licensed CC BY 4.0

Where to use it

Companies that serve this model through an API: 1. Prices per million tokens, cheapest first.

ProviderInputiOutputiContextiUptime (24 h)i
OpenAIOfficial
$15$60200K100.0%

Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.

Use it in your code

Call o1 through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "openai/o1", "messages": [{"role": "user", "content": "Hello! What can you do?"}]}'

The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.

What it costs in practice

  • 1,000 chat replies
    ≈ 500 tokens in, 300 out each
    $25.50
  • Summarise a 100-page document
    ≈ 50,000 tokens in, 1,000 out
    $0.81
  • An app with 10,000 requests a day for a month
    ≈ 1,000 tokens in, 400 out each
    $11,700

Cost calculator →

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Frequently asked questions

How much does o1 cost?
o1 costs $15 per million input tokens and $60 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $25.50.
What is the context window of o1?
o1 can read up to 200,000 tokens in one request, about 375 pages of text. It can write up to 100,000 tokens in a single answer.
Is o1 open source?
No. o1 is a closed model: its weights are not published, so you use it through OpenAI’s own apps and API, or through cloud providers.
Who makes o1?
o1 is made by OpenAI. It became available through the API on December 17, 2024.
How good is o1?
o1 has an overall index of 141.9 in Epoch AI’s independent tests, ranking #89 of 136 models we track.
Can o1 read images?
Yes. Besides text, it accepts images and files such as PDFs as input.
What are the alternatives to o1?
Models with a similar price from other companies include Claude Opus 4.1, Fugu Ultra v2 and MiMo-V2.6-Pro-UltraSpeed. You can compare them side by side on this page.