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OpenAI

o3:free

o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks. It also excels at technical writing and instruction-following....

TextReasoningToolsFilesVision200KCache
InputFree
OutputFree
Context200K
Endpointsopenai

Capabilities

ReasoningToolsVisionFilesCacheStructured

Modalities

Input
imagetextfile
Output
text

Quick stats

Context window200K
Max output100K
Modechat
TokenizerGPT
Knowledge cutoff2024
ModeratedYes

Performance

Loading performance data...

Supported parameters

ParameterAlwaysDefault
include_reasoning-
max_tokens-
reasoning-
response_format-
seed-
structured_outputs-
tool_choice-
tools-
§ 01

Pricing

Input price$0.00 · 1M tokens
Output price$0.00 · 1M tokens
Context window200K tokens
Compatible endpointsopenai
VendorOpenAI
§ 02

Call o3:free from your code

Point any OpenAI-compatible SDK at UnoRouter and request the model by name. Replace YOUR_API_KEY with a real key from your dashboard.

bash
curl https://api.unorouter.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "o3:free",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Sign in to auto-fill your API key

§ 03

Frequently asked questions

How much does o3:free cost per 1M tokens?

Input is priced at $0.00 per 1M tokens, output at $0.00 per 1M tokens. Billing is per token, no rounding to batch sizes.

How do I access o3:free via API?

Send requests to the UnoRouter /v1/chat/completions endpoint with model=o3:free. Any OpenAI-compatible client library works. Authentication uses a standard Bearer token.

What is the context window of o3:free?

o3:free supports a context window of 200K tokens, shared between your prompt and the model's response.

§ 04

Similar models

Try o3:free now

Create an API key and start making requests in under a minute.

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