Overview

The o1 model is trained to spend additional inference-time compute on internal reasoning before producing a response. Strong on math, coding, and science benchmarks.

History

o1 became available via the OpenAI API on 2024-12-17.

Training & availability

Training data has a knowledge cutoff of 2023-10-31 — information about events after that date is unlikely to appear in the model's responses. OpenAI has not released the underlying model weights — access is via their hosted API only.

Capabilities

Context window: 200K tokens.
Max output: 100K tokens.
Input modalities: text, image.
Intelligence Index: 76.2/100.

Strongest categories: Math (89), Reasoning (78), Coding (62).

Recommended for: vision, math, agentic, long-context, reasoning.

Limitations

The knowledge cutoff is 30 months old — this model will not know about recent events, releases, or API changes.
At $60.00/1M output tokens, this is in the premium tier — verify cost-per-value for high-volume workloads.

Pricing

Input: $15.0000 per 1M tokens
Output: $60.0000 per 1M tokens

Use the cost calculator above to estimate monthly spend for your workload.

Quick start

Minimal example using the openai API. Copy, paste, replace the key.

from openai import OpenAI

client = OpenAI(api_key="sk-...")
resp = client.chat.completions.create(
    model="o1",
    messages=[{"role": "user", "content": "Explain quantum computing in one sentence."}],
)
print(resp.choices[0].message.content)

Cost calculator

Estimate your monthly bill. Presets are typical workload sizes.

Input tokens / month5.0M

@ $15/1M

Output tokens / month2.0M

@ $60/1M

Input cost

$75

5.0M × $15/1M

Output cost

$120

2.0M × $60/1M

Total / month

$195

$2340 / year

Benchmarks

Benchmark	Score	Source
AIME 2024Math	83.3% accuracy	Self-reported OpenAI o1 system card
Aider PolyglotCoding	61.7% pass@2	Third-party Papers With Code
GPQA DiamondReasoning	78% accuracy	Self-reported OpenAI o1 system card

Integrations & tooling support

Tool calling: Supported
Structured outputs: Supported

Price vs quality

Overpriced

Mid-tier performance at frontier pricing.

Quality percentile: 72.3%
Effective price: $48.75/1M
Pricing breakdown: $15/1M in
$60/1M out

o1

Intelligence Index