Models / o3ID: openai/o3
reasoning model by OpenAI

o3

o3 from OpenAI — 200K-token context, multimodal vision, function calling.

PlaygroundQuick Start
Context window200K
Max output33K
Maker

OpenAI

Served On

OpenAI

Specifications

Context window, ranked against other reasoning models

Proportional scale: 0 to 200K tokens. Not ranked, no published context window: o1, o3-mini, gpt-5.5-pro, kimi-k2-thinking, gpt-5-pro, gpt-5.4-nano-2026-03-17.

Context window

200.0K

tokens
Max output

33K

tokens
Modality

reasoning

Vision
Function calling
System prompt

Pricing

Rates are read live

Pricing for o3 is fetched from the live catalogue on load, so it is never served from a cache that could outlive a repricing.

Availability

Not enough data yet

We have not collected enough health probes for this model to publish an uptime or latency figure. A percentage from a handful of samples is fabricated precision, so none is shown until the sample count supports one.

How o3 is billed

Billed at the provider's list price, with no per-token markup.

Exact list price
Tokens settle at the published rate of the model that served your call.
Cache discounts passed through
Provider prompt-caching discounts reach your balance with no added fee.
Cost on every response
Each response carries the x-nr-request-cost header, so you can reconcile spend per request.

More from OpenAI

whisper-1o1gpt-5.5-progpt-4o-mini-tts-2025-12-15

Start building with o3

One API key, three steps. Choose your tool to begin.

  1. Get a key

    Create API key

  2. Set your API key

    export NROUTER_API_KEY="<YOUR_API_KEY>"

  3. Configure Claude Code

    Choose a tool, then copy its setup from the panel.

npm install -g @anthropic-ai/claude-code
Claude Code · openai/o3
# Point Claude Code to nRouter gateway
export ANTHROPIC_BASE_URL="https://api.nrouter.ai"
export ANTHROPIC_API_KEY="$NROUTER_API_KEY"

# Launch with openai/o3
claude --model openai/o3

Frequently asked questions

What is o3?

o3 from OpenAI — 200K-token context, multimodal vision, function calling.

How much does o3 cost?

o3 is billed at the provider's list price on nRouter with no per-token markup — tokens settle at the exact upstream rate. Input and output rates are read live, so see the pricing section above for the current figures.

What is the context length of o3?

o3 supports a 200,000-token context window. It can generate up to 32,768 output tokens per request.

Does o3 support tool calling and structured outputs?

Yes. o3 supports tool calling (function calling), so it can invoke external tools and APIs during a conversation.

What inputs and outputs does o3 support?

o3 takes text and images as input and returns text as output.

How do I use o3 via nRouter?

Use any OpenAI-compatible client: point it at https://api.nrouter.ai/v1 with your nRouter API key and set the model to "openai/o3". The quick-start panel above has a copy-paste curl command for this model.

When was o3 released?

o3 was released on April 16, 2025.

Where is the o3 documentation?

Start at nrouter.ai/docs. The quick-start guide (nrouter.ai/docs/getting-started/quick-start) covers API keys and your first request, and the API reference (nrouter.ai/docs/api-reference) lists every parameter.

What other text models does OpenAI have?

Other OpenAI text models on nRouter include Whisper 1 (nrouter.ai/models/whisper-1), o1 (nrouter.ai/models/o1), GPT 5.5 Pro (nrouter.ai/models/gpt-5.5-pro), GPT 4o Mini TTS (nrouter.ai/models/gpt-4o-mini-tts-2025-12-15).

Pricing is live — see above for current rates.