OpenAI · LLM API pricing

o3 API pricing: cheapest provider

2 providers sell o3. OpenAI is cheapest, and listed prices are close.

Cheapest$3.50per 1M · OpenAI
Input · output$2.00 / $8.00per 1M tokens
Price gap1.0×across 2 providers
Context200Kmax tokens

$3.50 OpenAIclose prices$3.50 Microsoft Azure AI Foundry

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Standard list prices in USD from each provider's pricing page · last price change Sep 28, 2026 · How we collect and rank prices

Ranked for your volume

o3 monthly cost by provider

Change the monthly tokens and the ranking updates instantly, using each provider's standard list price.

Input tokens per month (millions)Prompts, context and documents you send.Output tokens per month (millions)Tokens the model generates.

More requirements: caching, context, features, provider

Cached share of input (%)0 = no caching. Only documented cache-read rates qualify.Required context per request (tokens)0 = any. Providers without a sufficient known limit are excluded.Required featureProvider requirement

Provider	Estimated / month	Input / 1M	Output / 1M	Cached input / 1M	Context
1 Microsoft Azure AI FoundryCloud platform - lowest for your volumePricing page	$36.00	$2.00	$8.00	$0.50	200,000
2 OpenAIModel developerPricing page	$36.00	$2.00	$8.00	$0.50	200,000

Order depends on listed price for your volume only. No provider pays for its position.

Input volume includes the cached share, not an additional token volume. This is a list-price estimate, not a quote: cache-write charges, cache eligibility/TTL, batch discounts, long-context surcharges, regional pricing and taxes are excluded. Check the provider's terms for your workload before switching.

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| o3 provider | Input / 1M tokens | Output / 1M tokens | 10M in + 2M out per month |
|---|---:|---:|---:|
| Microsoft Azure AI Foundry | $2.00 | $8.00 | $36.00 |
| OpenAI | $2.00 | $8.00 | $36.00 |

Standard list prices as of Oct 31, 2026. Source: [AISelect.online](https://aiselect.online/models/o3)

Price history

The cheapest price has not changed since tracking started on Sep 28, 2026: $3.50 per 1M tokens at OpenAI. All price changes

Switch to the cheapest provider

Switch to OpenAI

Already using the OpenAI SDK? Change the base URL, key and model name:

from openai import OpenAI
import os

client = OpenAI(
    base_url="https://api.openai.com/v1",
    api_key=os.environ["OPENAI_API_KEY"],
)
response = client.chat.completions.create(
    model="o3",
    messages=[{"role": "user", "content": "Hello"}],
)

Base URL from OpenAI's API docs, model name from the open pricing datasets. Check the model page in OpenAI's docs before you switch production traffic.

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Before you pick a provider

The developer's own API (OpenAI) has the lowest listed blended price for o3.

2 of 2 providers list a cached-input price. Repeated system prompts or documents can cost much less there than the standard input rate shown above.

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All OpenAI API prices - All LLM API prices - Watch o3 prices (RSS) - Methodology