OpenAI o3
FrontierLast verified: June 2026· OpenAI OpenAI o3 pricing
Reasoning-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 →
When to choose OpenAI o3
A dedicated reasoning model, and the billing detail is the thing to plan around: reasoning tokens are charged at the output rate, so a hard problem can cost several times what its visible answer suggests. The $2 in and $8 out headline reads mid-tier; the effective rate on a reasoning-heavy route does not. It earns that on genuinely hard maths, logic, and multi-step problems where a cheaper model fails outright rather than fails slightly. For everyday knowledge and context work it is the wrong instrument, and its 200K window is narrower than the long-context rows here.
OpenAI o3 sits close enough to OpenAI o4-mini on price that the two are usually decided together. That comparison is written once, on the models table, rather than argued twice from opposite sides.
What OpenAI o3 costs in practice
The headline arithmetic puts a 50M/10M month at $180, identical to GPT-4.1 because the rates are identical. The real figure is higher by an amount only your own traces can tell you, because reasoning tokens bill at the output rate and a hard problem can spend a great many of them before the visible answer begins. Filling the 200K window costs 40 cents of input, so context is not where the money goes here — thinking is. Budget this row by cost per solved problem rather than cost 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.
Where OpenAI o3 fits in a routing setup
Reasoning rows sit outside the ordinary routing ladder: you escalate to them by problem type rather than by difficulty score. The sensible arrangement is a general row handling everything until a class of problem is identified as reasoning-shaped, and only those requests coming here. For scale, Gemini 2.5 Pro runs to $163 on the reference month against $180 here without being a reasoning model at all — a reminder that what you are paying for on this row is the thinking tokens rather than the sticker.
Cheaper alternatives to OpenAI o3
The models immediately below OpenAI o3 on blended cost, nearest first. A swap only pays if quality holds on the routes you move — see the LLM cost optimization playbook for how to prove that before you move them.
Frequently asked questions
How much does OpenAI o3 cost?
OpenAI o3 bills $2.00 per million input tokens and $8.00 per million output tokens — $3.50 per million blended at a three-to-one input:output split. A workload of 50M input and 10M output tokens per month works out at about $180. Confirm current pricing with the provider.
What is OpenAI o3's context window?
OpenAI o3 has a 200K-token context window. One request that fills the whole window costs about $0.40 at the input rate, before the reply is billed.
Where does OpenAI o3 sit on price?
At $3.50 per million blended — three input tokens for every output token — OpenAI o3 is dearer than 10 of the 19 models tracked here and cheaper than 7. Output bills at 4x the input rate, and the nearest cheaper model on this table is Gemini 2.5 Pro at $3.44 blended.
Related concepts: context window, model routing, prompt caching, evals.