GPT-5 Nano
Where it stands
Quality in independent tests against price, next to 135 other models. Up means more capable, left means cheaper.
About this model
GPT-5 Nano is an AI model from OpenAI, made available through the API on August 7, 2025. It can read up to 400,000 tokens in one request, roughly 750 pages of text, and write up to 128,000 tokens in a single answer. Besides text, it accepts images and files such as PDFs as input.
Through the API it costs $0.05 per million input tokens and $0.40 per million output tokens. Its pricing puts it among the more affordable models we track, which makes it a good fit for high-volume tasks.
It supports extended reasoning: it can "think" step by step before answering, which helps on maths, code and complex questions. It can call tools and functions, so developers can connect it to search, databases or other software.
Quality scores
Rankings →- GPQA DiamondVery hard multiple-choice questions in biology, physics and chemistry, written by PhD experts. Random guessing scores 25%.69.4%#83 of 116
- AIME mathCompetition-level math problems in the style of the American Invitational Mathematics Examination. Share solved.81.1%#65 of 112
- FrontierMathOriginal, unpublished math problems written by professional mathematicians, from advanced to research level. Share solved.20.0%#61 of 73
- SimpleQA VerifiedShort factual questions. Measures how often the model gets facts right instead of making something up.11.7%#66 of 69
Where to use it
Companies that serve this model through an API: 4. Prices per million tokens, cheapest first.
| Provider | Inputi | Outputi | Contexti | Uptime (24 h)i |
|---|---|---|---|---|
OpenAIOfficialCheapest | $0.025 | $0.20 | 400K | 100.0% |
Azure | $0.05 | $0.40 | 400K | 100.0% |
OpenAIOfficial | $0.05 | $0.40 | 400K | 99.9% |
Azure | $0.055 | $0.44 | 400K | 100.0% |
Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.
Use it in your code
Call GPT-5 Nano through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.
curl https://openrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "openai/gpt-5-nano", "messages": [{"role": "user", "content": "Hello! What can you do?"}]}'import os
from openai import OpenAI
client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"])
reply = client.chat.completions.create(
model="openai/gpt-5-nano",
messages=[{"role": "user", "content": "Hello! What can you do?"}],
)
print(reply.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://openrouter.ai/api/v1", apiKey: process.env.OPENROUTER_API_KEY });
const reply = await client.chat.completions.create({
model: "openai/gpt-5-nano",
messages: [{ role: "user", content: "Hello! What can you do?" }],
});
console.log(reply.choices[0].message.content);The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.
What it costs in practice
- 1,000 chat replies$0.145
- Summarise a 100-page document$0.0029
- An app with 10,000 requests a day for a month$63.00
Similar-priced alternatives
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|---|---|---|---|---|
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| $0.06 | $0.25 | 128K | Compare with ⇄ | |
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News about OpenAI
See all →Frequently asked questions
- How much does GPT-5 Nano cost?
- GPT-5 Nano costs $0.05 per million input tokens and $0.40 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $0.145.
- What is the context window of GPT-5 Nano?
- GPT-5 Nano can read up to 400,000 tokens in one request, about 750 pages of text. It can write up to 128,000 tokens in a single answer.
- Is GPT-5 Nano open source?
- No. GPT-5 Nano is a closed model: its weights are not published, so you use it through OpenAI’s own apps and API, or through cloud providers.
- Who makes GPT-5 Nano?
- GPT-5 Nano is made by OpenAI. It became available through the API on August 7, 2025.
- How good is GPT-5 Nano?
- GPT-5 Nano has an overall index of 139.4 in Epoch AI’s independent tests, ranking #99 of 136 models we track.
- Can GPT-5 Nano read images?
- Yes. Besides text, it accepts images and files such as PDFs as input.
- What are the alternatives to GPT-5 Nano?
- Models with a similar price from other companies include Solar Mini 4, Schematron V2 Small and Nemotron 3 Nano 30B A3B. You can compare them side by side on this page.