OpenAI o3
FrontierReasoning-optimized model. Reasoning tokens are billed as output — confirm current pricing with OpenAI.
- Input / 1M
- $2.00
- Output / 1M
- $8.00
- Context
- 200K tokens
- Provider
- OpenAI
Pricing verified June 2026. Prices change frequently. Always confirm against the provider’s official pricing page before relying on these figures for budgeting. Official pricing →
What OpenAI o3 is best for
Hard reasoning, math, and coding where a dedicated reasoning model helps.
Use it for the hardest reasoning, long-horizon agentic work, and routes where output quality is load-bearing. Avoid it for high-volume, low-stakes calls like classification or extraction — those belong on a cheaper tier.
OpenAI o3 cost by volume
Estimated monthly cost at three realistic volumes, at $2.00 input / $8.00 output per million tokens.
| Scenario | Input / mo | Output / mo | Est. cost / mo |
|---|---|---|---|
| Prototype | 2M | 0.5M | $8 |
| Growing product | 50M | 10M | $180 |
| At scale | 500M | 100M | $1,800 |
Plug in your own numbers with the cost calculator.
How to cut your OpenAI o3 bill
The headline price isn’t the lever — your usage pattern is. The biggest reductions come from how you route and structure requests, not from switching models alone:
- Route low-stakes calls to a cheaper tier and keep OpenAI o3 on the routes where its strengths matter.
- Cache large stable prompt prefixes so repeated context bills at a fraction of the price.
- Batch non-urgent work, and trim oversized context by retrieving instead of stuffing.
- Add fallback chains so a timeout doesn’t trigger an expensive retry.
Do it behind evals so quality holds — that combination is how teams cut 30–60% without regressions.
Context window: 200K tokens
OpenAI o3’s context window bounds how much it can consider at once — system prompt, history, retrieved docs, and the response all draw from those 200K tokens. A larger window enables whole-codebase reasoning and long documents, but using more of it costs more per request — so retrieval and caching still matter even when the window is large.
Cheaper alternatives to OpenAI o3
By blended cost (3:1 input:output). The right swap depends on whether quality holds on your routes — always validate with evals.
Frequently asked questions
How much does OpenAI o3 cost?
OpenAI o3 costs $2.00 per million input tokens and $8.00 per million output tokens. A workload of 50M input and 10M output tokens per month would cost about $180. Confirm current pricing with the provider.
What is OpenAI o3's context window?
OpenAI o3 has a 200K-token context window. Reasoning-optimized model. Reasoning tokens are billed as output — confirm current pricing with OpenAI.
Is OpenAI o3 the right model for my workload?
Hard reasoning, math, and coding where a dedicated reasoning model helps. The cheapest correct model is workload-specific — route low-stakes calls to a cheaper tier and reserve OpenAI o3 for work where its strengths matter, validated by evals.