OpenAI · Released Apr 16, 2025o3
Deliberate o-series reasoner for hard math, coding, and multi-step analysis.
- Capability
- 146.9ECI · #63 of 148
- Input
- $2.00per 1M tokens
- Output
- $8.00per 1M tokens
- Context
- 200K100K max output
What it costs
- Input
- $2.00per million tokens
- Output
- $8.00per million tokens
- Cached input
- $0.50per million tokens
- Blended (3:1)
- $3.50pricier than 80% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $8.00 |
| Team assistant25M input + 5M output tokens | $90.00 |
| Production app250M input + 50M output tokens | $900.00 |
Official OpenAI API price, as listed on models.dev.
Independent benchmarks
#63 of 148 scored models
The shaded band is Epoch AI’s confidence range (144.9–148.6); the tick marks the median scored model.
Scores from Epoch AI, run independently of OpenAI.
The details
- Lab
- OpenAI
- Released
- Apr 16, 2025
- Knowledge cutoff
- May 2024
- Context window
- 200,000 tokens
- Max output
- 100,000 tokens
- Inputs
- Text, Images, PDFs
- Output
- Text
- Reasoning
- Adjustable effort low · medium · high
- Tool calling
- Yes
- Structured output
- Yes
- Weights
- Proprietary
- API model ID
o3on OpenAI- Availability
- 18 API providerslisted on models.dev
What OpenAI claims
Published by the lab at launch. Settings vary, so compare these only with care.
| Benchmark | Score | Setting | Source |
|---|---|---|---|
| Aider Polyglot | 81.3 percent correct | — | Source |
More from OpenAI
About o3
How much does o3 cost?
o3 costs $2.00 input / $8.00 output per million tokens (official OpenAI API price). Cached input is $0.50 per million tokens. At a 3:1 input-to-output mix that is $3.50 per million tokens, more expensive than 80% of the 360 priced models we track.
What is the context window of o3?
o3 accepts up to 200,000 tokens per request and can write up to 100,000 tokens in one response.
How good is o3?
Epoch AI gives o3 a Capabilities Index score of 146.9 (likely range 144.9–148.6), ranking it #63 of 148 models Epoch has scored. Epoch AI benchmark results: GPQA Diamond 81.8%, FrontierMath Tiers 1–3 33.3%, OTIS Mock AIME 2024–2025 84.4%, SWE-bench Verified 62.3%, SimpleQA Verified 49.4%.
Is o3 open source?
No. o3 is proprietary; you use it through OpenAI’s API or partner platforms.
What inputs does o3 support?
o3 accepts text, images and PDFs and replies in text. It is a reasoning model with low, medium and high effort settings, supports tool calling and can return structured JSON output.
When was o3 released?
OpenAI released o3 on Apr 16, 2025. Its training data runs to May 2024.
What are the best alternatives to o3?
The closest current models from other labs on capability, price and release date are Gemini 2.5 Pro (Google, ECI 145.3, $1.25 / $10.00), Claude Sonnet 4.5 (Anthropic, ECI 146.8, $3.00 / $15.00), Qwen3 Max (Alibaba (Qwen), ECI 142.4, $1.20 / $6.00) and GLM-5 (Z.ai (Zhipu), ECI 145.8, $1.00 / $3.20).