o3 Pro
o3 Pro applies maximum reasoning compute to the o3 architecture, delivering the deepest chain-of-thought analysis available for the most demanding mathematical, scientific, and analytical problems.
View API reference- Input and output price
- Input $20, Output $80, Per 1M tokens
- 24h uptime
- Loading AI Gateway uptime
import { streamText } from 'ai'
const result = streamText({ model: 'openai/o3-pro', prompt: 'Why is the sky blue?'})Copy link to headingPlayground
Try out o3 Pro by OpenAI. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days.
o3 Pro
Copy link to headingProviders
Route requests across multiple providers. Copy a provider slug to set your preference. Visit the docs for more info. Using a provider means you agree to their terms, listed under Legal.
| Provider |
|---|
Copy link to headingUptime24 hours
Direct request success rate on AI Gateway and per-provider. Visit the docs for more info.
Copy link to headingThroughput24 hours
P50 throughput on live AI Gateway traffic, in tokens per second (TPS). Visit the docs for more info.
Copy link to headingLatency24 hours
P50 time to first token (TTFT) on live AI Gateway traffic, in milliseconds. View the docs for more info.
Getting started
Call o3 Pro through AI Gateway with the AI SDK generateText and streamText functions, or through the OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages APIs by changing the base URL. AI Gateway authenticates the request and routes it to an available provider.
Install the AI SDK (pnpm add ai dotenv), create an API key from the API Keys page, and set it as AI_GATEWAY_API_KEY in your environment. Full setup is covered in the text generation quickstart.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', prompt: 'Why is the sky blue?', });
console.log(result.text);}
main().catch(console.error);Top-level parameters
The same o3 Pro request in each API format AI Gateway supports.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', system: 'You are a concise technical assistant.', prompt: 'Summarize the tradeoffs between static generation and SSR.', maxOutputTokens: 1024, });
console.log(result.text);}
main().catch(console.error);Standard parameters like prompt, messages, temperature, and tools work as documented in the AI SDK docs. These are the parameters with model-specific behavior.
| Parameter | Type | Required | Description |
|---|---|---|---|
model | string | Yes | Model ID in the form creator/model, e.g. openai/o3-pro. AI Gateway routes the request to an available provider. |
maxOutputTokens | number | No | Hard cap on generated tokens. o3 Pro supports up to 100,000 output tokens. Reasoning tokens count toward this limit. |
reasoning | 'provider-default' | 'none' | 'minimal' | 'low' | 'medium' | 'high' | 'xhigh' | No | Provider-agnostic reasoning effort, available in AI SDK 7 or later. Maps to the provider’s native reasoning configuration; reasoning settings under providerOptions take precedence when both are set. See the Reasoning section below. |
providerOptions | Record<string, JSONValue> | No | AI Gateway routing options under gateway, plus any provider-native options under the provider’s own namespace — see the table below. |
Input limits
| Input | Formats | Sources | Max count | Max size | Limits |
|---|---|---|---|---|---|
| Text | — | — | — | — | Prompt and response share the 200K-token context window |
| Image | — | URL, base64, Uint8Array | — | — | Sent as image parts in messages; counts as input tokens |
| — | URL, base64, Uint8Array | — | — | Sent as file parts in messages; counts as input tokens |
Provider options
Set AI Gateway routing options under providerOptions.gateway. For provider-specific options, pass them under the provider’s namespace as documented by the AI SDK.
Learn more in the AI SDK openai provider docs.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', prompt: 'Why is the sky blue?', providerOptions: { gateway: { only: ['openai'], }, }, });
console.log(result.text);}
main().catch(console.error);These AI Gateway routing options apply to every model. Provider-specific options pass through under the provider’s own namespace (for example providerOptions.anthropic) exactly as documented by the AI SDK.
| Parameter | Type | Required | Description |
|---|---|---|---|
providerOptions.gateway.only | string[] | No | Restrict routing to these provider slugs. Requests fail over only within the listed providers. |
providerOptions.gateway.order | string[] | No | Preferred provider order. Listed providers are tried first; unlisted providers remain available as fallbacks. |
providerOptions.gateway.sort | 'cost' | 'ttft' | 'tps' | No | Rank candidate providers by price, time to first token, or tokens per second instead of the default routing order. |
providerOptions.gateway.zeroDataRetention | boolean | No | Route only to providers with a zero-data-retention policy for this model. |
Routing across providers
AI Gateway serves the same model through multiple providers and fails over automatically. order expresses a preference while keeping every provider eligible; only is a hard allowlist — if none of the listed providers are available the request fails instead of falling back.
Options under a provider's own namespace (for example providerOptions.anthropic) are forwarded to that provider with the request. Providers ignore option namespaces that don't apply to them, so it is safe to set provider options alongside gateway routing options.
Reasoning
AI Gateway bridges reasoning across every API format. The AI SDK exposes a provider-agnostic top-level reasoning level (none, minimal, low, medium, high, or xhigh); the Chat Completions and Responses formats take the same effort under reasoning.effort; and the Anthropic Messages format uses a native thinking token budget. Whichever you send, the gateway maps it to the target model’s native configuration, converting between effort levels and token budgets as needed. Reasoning-related settings under providerOptions take full precedence over the top-level reasoning value and are never merged. Reasoning tokens typically count toward your output-token usage, though how they’re reported and billed varies by provider.
Learn more in the AI Gateway reasoning guide.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', prompt: 'Explain the Monty Hall problem step by step.', reasoning: 'high', });
console.log(result.text);}
main().catch(console.error);Image input
Send images alongside text as message parts. Images count as input tokens.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', messages: [ { role: 'user', content: [ { type: 'text', text: 'Describe this image.' }, { type: 'image', image: 'https://example.com/photo.jpg' }, ], }, ], });
console.log(result.text);}
main().catch(console.error);PDF input
Attach PDFs as file parts. Their contents count as input tokens.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', messages: [ { role: 'user', content: [ { type: 'text', text: 'Summarize this document.' }, { type: 'file', mediaType: 'application/pdf', data: 'https://example.com/document.pdf', }, ], }, ], });
console.log(result.text);}
main().catch(console.error);Tool calling
Expose tools the model can call. Define each tool’s inputs with a Zod schema.
import { generateText, tool } from 'ai';import { z } from 'zod';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'openai/o3-pro', prompt: 'What is the weather in San Francisco?', tools: { getWeather: tool({ description: 'Get the current weather for a location', inputSchema: z.object({ location: z.string() }), execute: async ({ location }) => ({ location, temperatureC: 18 }), }), }, });
console.log(result.text);}
main().catch(console.error);Copy link to headingAbout o3 Pro
o3 Pro was released on June 10, 2025 as the premium tier of the o3 reasoning model family. It applies maximum compute to each reasoning request, enabling the deepest chain-of-thought analysis available from OpenAI.
The additional compute produces more thorough deliberation: the model explores more solution paths, checks its work more exhaustively, and arrives at conclusions with higher confidence. On the hardest mathematical, scientific, and analytical problems, this translates to measurably better accuracy.
The tradeoff is cost and latency. o3 Pro is the most expensive model in the o3 family and takes the longest to respond. For problems where the difference between good and best matters, that investment is justified. For standard reasoning tasks, o3 or o3-mini provide sufficient quality at substantially lower cost.
Copy link to headingWhat To Consider When Choosing a Provider
- Configuration: o3 Pro applies the most compute per request of any o3 variant. Use it when the problem genuinely requires exhaustive deliberation and the quality difference is consequential.
- Configuration: Most teams reserve o3 Pro for their hardest queries, routing standard reasoning traffic to o3 or o3-mini.
- Zero Data Retention: Zero Data Retention is offered on a per-provider and model basis. See the documentation for details.
- Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.
Copy link to headingWhen to Use o3 Pro
Best for
- Frontier mathematical reasoning: The hardest proofs, competition problems, and mathematical research
- Critical scientific analysis: Complex derivations and multi-step scientific reasoning where errors have consequences
- Exhaustive code analysis: Security audits and algorithmic verification requiring thorough deliberation
- Research-grade reasoning: Academic and research problems that benefit from the deepest available analysis
- High-stakes analytical decisions: Analyses where maximum reasoning depth directly impacts outcomes
Consider alternatives when
- Standard reasoning: O3 for most reasoning tasks at lower cost
- Budget-friendly reasoning: O3-mini for cost-efficient chain-of-thought on routine problems
- General-purpose tasks: GPT-5.2 pro for tasks that need premium quality but not specialized reasoning
- Fast responses: Any standard model when response time matters more than reasoning depth
Copy link to headingConclusion
o3 Pro applies maximum compute within the o3 family to the hardest problems. For mathematical, scientific, and analytical challenges where reasoning depth directly determines quality, it is the premium tier of the o3 lineup.
Copy link to headingFrequently Asked Questions
How does o3 Pro differ from standard o3?
It applies more compute per request, enabling deeper and more exhaustive chain-of-thought reasoning. The improvement is most significant on the hardest problems.
When is the premium cost justified?
For frontier mathematical proofs, critical scientific analysis, security audits, and other problems where the deepest possible reasoning produces meaningfully better outcomes.
What context window does o3 Pro support?
200K tokens, matching the o3 family.
Is o3 Pro slower than o3?
Yes. The additional reasoning compute increases response time. Reserve it for problems where depth justifies the wait.
How does AI Gateway handle authentication for o3 Pro?
AI Gateway accepts a single API key or OIDC token for all requests. You don't embed OpenAI credentials in your application; AI Gateway routes and authenticates on your behalf.
What are typical latency characteristics?
This page shows live throughput and time-to-first-token metrics measured across real AI Gateway traffic.