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GPT-5 Nano

Reasoning model by OpenAI.

Compact reasoning model designed for high-throughput, low-cost analytical evaluation and lightweight reasoning tasks.

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Models / GPT-5 NanoID: openai/gpt-5-nano

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: gpt-5.2-pro-2025-12-11, gpt-5.4-pro, grok-4-1-fast-non-reasoning, grok-4-1-fast-reasoning, gpt-5.2-pro.

Context window

—

Max output

—

Modality

reasoning

Vision
Function calling
System prompt

Pricing

Rates are read live

Pricing for gpt-5-nano 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 GPT-5 Nano 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

gpt-oss-120b-1gpt-6.1-solgpt-5.2-pro-2025-12-11gpt-audio-1.5

Start building with gpt-5-nano

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/gpt-5-nano
# Point Claude Code to nRouter gateway
export ANTHROPIC_BASE_URL="https://api.nrouter.ai"
export ANTHROPIC_API_KEY="$NROUTER_API_KEY"

# Launch with openai/gpt-5-nano
claude --model openai/gpt-5-nano

FAQs

What is GPT-5 Nano?

Compact reasoning model designed for high-throughput, low-cost analytical evaluation and lightweight reasoning tasks.

How much does GPT-5 Nano cost?

GPT-5 Nano 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.

Does GPT-5 Nano support tool calling and structured outputs?

Yes. GPT-5 Nano supports tool calling (function calling), so it can invoke external tools and APIs during a conversation.

What inputs and outputs does GPT-5 Nano support?

GPT-5 Nano takes text and images as input and returns text as output.

How do I use GPT-5 Nano 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/gpt-5-nano". The quick-start panel above has a copy-paste curl command for this model.

When was GPT-5 Nano released?

GPT-5 Nano was released on August 7, 2025.

Where is the GPT-5 Nano 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 GPT-OSS 120B 1 (nrouter.ai/models/gpt-oss-120b-1), GPT-6.1 Sol (nrouter.ai/models/gpt-6.1-sol), GPT-5.2 Pro (nrouter.ai/models/gpt-5.2-pro-2025-12-11), GPT Audio 1.5 (nrouter.ai/models/gpt-audio-1.5).