Where is the GPT-5 Nano documentation?

The GPT-5 Nano documentation on OpenRouter includes the GPT-5 is now live blog post. The quickstart covers API keys and your first request, and the API reference lists every parameter.

How much does GPT-5 Nano cost?

GPT-5 Nano costs $0.05/M input tokens and $0.40/M output tokens, with separate rates for Cache Read at $0.01/M tokens.

What is the context length of GPT-5 Nano?

GPT-5 Nano has a 400,000 token context window.

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

Yes. GPT-5 Nano accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

What inputs and outputs does GPT-5 Nano support?

GPT-5 Nano accepts text, images, and files such as PDFs as input and returns text.

Which providers serve GPT-5 Nano?

GPT-5 Nano is served by 2 providers on OpenRouter: OpenAI and Azure. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

When was GPT-5 Nano released?

GPT-5 Nano was released on August 7, 2025. Its knowledge cutoff is May 31, 2024.

OpenAI: GPT-5 Nano

openai/gpt-5-nano

Compare

GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger counterparts, it retains key instruction-following and safety features. It is the successor to GPT-4.1-nano and offers a lightweight option for cost-sensitive or real-time applications.

Modalities

In / out price

$0.05 / $0.40per 1M

Context

400K

Released

Aug 7, 2025

Knowledge cutoff

May 2024

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).

Latency / throughput


	$0.05	$0.40	$0.005	2.78s	106 tok/s	100.00%
	$0.05	$0.40	$0.01	1.32s	49 tok/s	100.00%
Not used in Standard routing:Why these endpoints are not used
Flex	$0.025	$0.20	$0.0025	3.15s	57 tok/s	100.00%
	$0.055	$0.44	$0.011	2.00s	111 tok/s	100.00%

Input $0.05Output $0.40
106 tok/s100.00% uptime
Input $0.05Output $0.40
49 tok/s100.00% uptime
Not used in Standard routing:Why these endpoints are not used
Input $0.025Output $0.20
Flex
57 tok/s100.00% uptime
Input $0.055Output $0.44
111 tok/s100.00% uptime

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Weighted average

Input

$0.03325/M tokens

Output

$0.3995/M tokens

GPT-5 Nano — Price history

Price history

No effective price data for this selection

		$0.0314	$0.400	41.2%	89.6%
		$0.0463	$0.397	8.8%	9.6%
Not used in Standard routing:Why these endpoints are not used
	Flex	$0.0175	$0.199	32.4%	0.4%
		$0.0209	$0.438	76.8%	0.4%

Effective in $0.0314Effective out $0.400
Token share
89.6%
Effective in $0.0463Effective out $0.397
Token share
9.6%
Not used in Standard routing:Why these endpoints are not used
Effective in $0.0175Effective out $0.199
FlexToken share
0.4%
Effective in $0.0209Effective out $0.438
Token share
0.4%

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Uptime (3d)

99.99%

Availability (3d)

99.98%

Availability over the last 3 days

Last 72 hours

Availability 99.98%

3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability

99.98%

Without Routing

99.30%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Benchmarks

Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.

Benchmark score summary for OpenAI: GPT-5 Nano (Artificial Analysis, Design Arena and Vals AI)
Source	Benchmark	Score
Artificial Analysis	GPT-5 nano (High) GPQA Diamond	67.6%
Artificial Analysis	GPT-5 nano (High) HLE	9.5%
Artificial Analysis	GPT-5 nano (High) IFBench	67.6%
Artificial Analysis	GPT-5 nano (High) τ²-Bench Telecom	36.5%
Artificial Analysis	GPT-5 nano (High) AA-LCR	45.0%
Artificial Analysis	GPT-5 nano (High) CritPt	0.0%
Artificial Analysis	GPT-5 nano (High) LiveCodeBench	78.9%
Artificial Analysis	GPT-5 nano (High) Terminal-Bench Hard	12.1%
Artificial Analysis	GPT-5 nano (High) MMLU-Pro	78.0%
Artificial Analysis	GPT-5 nano (High) AIME 2025	83.7%
Artificial Analysis	GPT-5 nano (Medium) GPQA Diamond	67.0%
Artificial Analysis	GPT-5 nano (Medium) HLE	8.7%
Artificial Analysis	GPT-5 nano (Medium) IFBench	65.9%
Artificial Analysis	GPT-5 nano (Medium) τ²-Bench Telecom	30.4%
Artificial Analysis	GPT-5 nano (Medium) AA-LCR	43.7%
Artificial Analysis	GPT-5 nano (Medium) CritPt	0.0%
Artificial Analysis	GPT-5 nano (Medium) LiveCodeBench	76.3%
Artificial Analysis	GPT-5 nano (Medium) Terminal-Bench Hard	17.4%
Artificial Analysis	GPT-5 nano (Medium) MMLU-Pro	77.2%
Artificial Analysis	GPT-5 nano (Medium) AIME 2025	78.3%
Artificial Analysis	GPT-5 nano (Minimal) GPQA Diamond	42.8%
Artificial Analysis	GPT-5 nano (Minimal) HLE	4.0%
Artificial Analysis	GPT-5 nano (Minimal) IFBench	32.5%
Artificial Analysis	GPT-5 nano (Minimal) τ²-Bench Telecom	25.7%
Artificial Analysis	GPT-5 nano (Minimal) AA-LCR	20.0%
Artificial Analysis	GPT-5 nano (Minimal) CritPt	0.0%
Artificial Analysis	GPT-5 nano (Minimal) LiveCodeBench	47.0%
Artificial Analysis	GPT-5 nano (Minimal) Terminal-Bench Hard	6.8%
Artificial Analysis	GPT-5 nano (Minimal) MMLU-Pro	55.6%
Artificial Analysis	GPT-5 nano (Minimal) AIME 2025	27.3%
Design Arena	GPT-5 nano (Default) Models Arena 3D Elo	945
Design Arena	GPT-5 nano (Default) Models Arena Code Categories Elo	1074
Design Arena	GPT-5 nano (Default) Models Arena Data Visualization Elo	1053
Design Arena	GPT-5 nano (Default) Models Arena Game Development Elo	1034
Design Arena	GPT-5 nano (Default) Models Arena UI Component Elo	1057
Design Arena	GPT-5 nano (Default) Models Arena Website Elo	1093
Vals AI	GPT 5 Nano AIME	81.2%
Vals AI	GPT 5 Nano CaseLaw v2	52.6%
Vals AI	GPT 5 Nano GPQA Diamond	63.4%
Vals AI	GPT 5 Nano LiveCodeBench	70.2%
Vals AI	GPT 5 Nano LegalBench	50.1%
Vals AI	GPT 5 Nano MATH 500	93.8%
Vals AI	GPT 5 Nano MedCode	30.4%
Vals AI	GPT 5 Nano MedQA	93.3%
Vals AI	GPT 5 Nano MedScribe	72.9%
Vals AI	GPT 5 Nano MGSM	89.3%
Vals AI	GPT 5 Nano MMLU Pro	76.1%
Vals AI	GPT 5 Nano MMMU Pro	70.9%
Vals AI	GPT 5 Nano MortgageTax	53.6%
Vals AI	GPT 5 Nano ProofBench v1	12.0%
Vals AI	GPT 5 Nano SAGE v1	30.4%
Vals AI	GPT 5 Nano TaxEval v2	67.4%

Available through EU in-region routing

OpenAI: GPT-5 Nano is available through EU in-region routing. Requests sent to eu.openrouter.ai are decrypted in the EU and routed only to shared provider endpoints in Europe (the EU/EEA, the UK, and Switzerland).

Providers in Europe

Azure

Prices in Europe

Azure: $0.055/M tokens input, $0.44/M tokens output

Base URL

https://eu.openrouter.ai/api/v1

Plan

Requires Business or Enterprise. Self-serve on Business: no contract, no monthly minimum. OpenRouter Business for EU in-region routing

Fails closed: if no shared provider endpoint in Europe is available, the request errors instead of leaving the region. Requests served by your own BYOK key go to your deployment’s region, which you control. In-region routing docs

More models from OpenAI

GPT Image 2.6 Sunburst

GPT Image 2.6 Sunburst is OpenAI's image generation and editing model optimized for detail: dense compositions, text-heavy layouts, and edits that keep details consistent from one edit to the next at medium or high quality, generating about 50% faster than GPT Image 2.5. It takes text and image inputs and produces images, with quality tiers from low to max, transparent backgrounds, and custom sizes in multiples of 16 pixels at aspect ratios from 1:3 to 3:1. GPT Image 2.6 introduces a complexity setting for how much the model plans before rendering, markup-guided edits, animated GIF output, and SVG output. Choose Flare instead when speed matters more than fine detail.

Image$8 / $30

GPT Image 2.6 Flare

GPT Image 2.6 Flare is OpenAI's image generation and editing model optimized for speed: fast iteration and interactive text-to-image and image-to-image workflows, generating about 50% faster than GPT Image 2.5. It takes text and image inputs and produces images, with quality tiers from low to max, transparent backgrounds, and custom sizes in multiples of 16 pixels at aspect ratios from 1:3 to 3:1. GPT Image 2.6 introduces a complexity setting for how much the model plans before rendering, markup-guided edits, animated GIF output, and SVG output. Choose Sunburst instead when detail and edit-to-edit consistency matter more than latency.

Image$8 / $30

GPT-6.1 Terra Pro

GPT-6.1 Terra Pro is the same underlying model as GPT-6.1 Terra, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6.1 Terra and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6.1 Terra instead.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$1 / $5

GPT-6.1 Terra Pro (batch)

GPT-6.1 Terra Pro is the same underlying model as GPT-6.1 Terra, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$0.50 / $2.50

GPT-6.1 Terra

GPT-6.1 Terra is the mid-tier model in OpenAI's GPT-6.1 series, priced below GPT-6.1 Sol. It is suited for everyday agentic, coding, and writing work, is particularly strong at understanding screenshots and on-screen content, and is efficient enough for high-volume workloads.

Text1.1M context$1 / $5

GPT-6.1 Terra (batch)

Text1.1M context$0.50 / $2.50

GPT-6 Luna Decisions

GPT-6 Luna Decisions is GPT-6 Luna served through OpenAI's Decisions API. Instead of generating text, it reads the content passed as state (text, JSON, or images) and returns typed, probabilistic answers to named questions in a single request: the probability of yes for a yes/no question (noul), a probability for every option plus the most likely one (choice), or a probability for every level of an ordered rubric plus the expected score (score).

It is built for classification, routing, moderation, and rubric grading where application code thresholds the returned numbers rather than parsing a chat reply. A request can carry up to 200 questions about the same content.

Decisions$0.10 / $0

GPT-6.1 Sol Pro

GPT-6.1 Sol Pro is the same underlying model as GPT-6.1 Sol, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6.1 Sol and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6.1 Sol instead.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$2 / $10

GPT-6.1 Sol Pro (batch)

GPT-6.1 Sol Pro is the same underlying model as GPT-6.1 Sol, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$1 / $5

GPT-6.1 Sol

GPT-6.1 Sol is an upgrade to GPT-6 Sol from OpenAI, positioned below the flagship GPT-6 Astra in the GPT-6 series. It is suited for agentic coding, computer use, document-heavy professional work, and multi-step business workflow automation, and approaches Astra-level results on these tasks at a much lower cost. Compared with GPT-6 Sol, it makes fewer factual errors and is more reliable at respecting explicit restrictions and user intent during agentic tasks.

Text1.1M context$2 / $10

GPT-6.1 Sol (batch)

Text1.1M context$1 / $5

GPT-6 Luna Pro

GPT-6 Luna Pro is the same underlying model as GPT-6 Luna, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6 Luna and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6 Luna instead.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$0.10 / $0.50

GPT-6 Luna Pro (batch)

GPT-6 Luna Pro is the same underlying model as GPT-6 Luna, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$0.05 / $0.25

GPT-6 Luna

GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol. It is suited for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic tasks, and at higher reasoning effort it can take on complex software engineering and computer-use tasks that previously called for a Sol-tier model. It shares the GPT-6 family's gains in factual reliability and its clearer, more concise communication style.

Text1.1M context$0.10 / $0.50

GPT-6 Luna (batch)

Text1.1M context$0.05 / $0.25

GPT-6 Sol Pro

GPT-6 Sol Pro is the same underlying model as GPT-6 Sol, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6 Sol and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6 Sol instead.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$2 / $10

GPT-6 Sol Pro (batch)

GPT-6 Sol Pro is the same underlying model as GPT-6 Sol, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$1 / $5

GPT-6 Sol

GPT-6 Sol is the cost-efficient high-end model in OpenAI's GPT-6 series, positioned below the flagship GPT-6 Astra and above the fast GPT-6 Luna tier. It is suited for demanding professional work, agentic coding, business workflow automation, and computer use, and is particularly strong at long-horizon software engineering tasks in real codebases. It approaches Astra-level factual reliability at a much lower cost and shares Astra's clearer, more concise communication style in technical and coding conversations.

Text1.1M context$2 / $10

GPT-6 Sol (batch)

Text1.1M context$1 / $5

GPT Astra Latest

This model always redirects to the latest model in the GPT Astra family.

Text1.1M context

OpenAI: GPT-5 Nano

Providers