# GPT-5 nano

> OpenAI's fastest, cheapest GPT-5 model — built for high-volume classification and summarization.

- Maker: OpenAI
- Line: GPT Nano
- Canonical page: https://ai-tldr.dev/models/gpt-5-nano/
- Updated: 2026-06-18

## In short

GPT-5 nano is the smallest, fastest, and lowest-cost model in OpenAI's GPT-5 family, released on August 7, 2025 alongside GPT-5 and GPT-5 mini. It is an API-only model aimed at high-volume, latency-sensitive work — OpenAI positions it for tasks like summarization and classification where speed and cost matter more than maximum reasoning depth. It has a 400K-token context window and costs $0.05 per million input tokens and $0.40 per million output tokens.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 400K (max output 128K) | [1] |
| Input price | $0.05 / 1M tokens (cached $0.005) | [2] |
| Output price | $0.40 / 1M tokens | [2] |
| Licence | Proprietary · API only | [1] |
| Released | 7 August 2025 | [3] |
| Parameters | Undisclosed | [1] |
| Knowledge cutoff | May 2024 | [1] |

## Sources

1. [GPT-5 nano on OpenRouter](https://openrouter.ai/openai/gpt-5-nano)
2. [GPT-5 nano — OpenAI API model page](https://developers.openai.com/api/docs/models/gpt-5-nano)
3. [Introducing GPT-5 — OpenAI announcement](https://openai.com/index/introducing-gpt-5/)

## Overview

GPT-5 nano is the smallest, fastest, and lowest-cost model in OpenAI's GPT-5 family, released on August 7, 2025 alongside GPT-5 and GPT-5 mini. It is an API-only model aimed at high-volume, latency-sensitive work — OpenAI positions it for tasks like summarization and classification where speed and cost matter more than maximum reasoning depth.

Despite its size, GPT-5 nano carries the generation's full 400,000-token context window and can produce up to 128,000 output tokens. It accepts both text and image input and returns text. Like the rest of the GPT-5 line it is a reasoning model with a configurable reasoning effort, so developers can dial thinking up for harder prompts or down to keep responses near-instant and cheap.

Pricing is the headline: at $0.05 per million input tokens and $0.40 per million output tokens, GPT-5 nano is OpenAI's cheapest GPT-5 model, with cached input at $0.005 per million tokens cutting the cost of repeated context further. It is offered via the OpenAI API as model id gpt-5-nano (snapshot gpt-5-nano-2025-08-07), and its knowledge cutoff is May 2024. It is the first entry in the GPT Nano line, succeeded by GPT-5.4 nano.

## Pricing

- Input: $0.05 / 1M tokens
- Cached input: $0.005 / 1M tokens
- Output: $0.40 / 1M tokens

Source: https://developers.openai.com/api/docs/models/gpt-5-nano

## Strengths

- Lowest-cost GPT-5 model — $0.05 input / $0.40 output per 1M tokens, with cached input at $0.005
- Very fast, low-latency responses suited to real-time and high-volume traffic
- Full 400K-token context window despite being the smallest GPT-5 variant
- Text + image input, so it can read screenshots and documents on a budget
- Configurable reasoning effort to trade speed against accuracy per request

## Best for

- Reach for it for high-throughput classification, tagging, and routing where per-call cost dominates.
- Reach for it for summarization of large volumes of text at the lowest price point.
- Reach for it as the cheap tier in a model-routing setup, escalating only hard prompts to GPT-5 mini or GPT-5.

## How to access

- [OpenAI API](https://developers.openai.com/api/docs/models/gpt-5-nano) — model id `gpt-5-nano`
- [OpenRouter](https://openrouter.ai/openai/gpt-5-nano) — model id `openai/gpt-5-nano`

## GPT Nano versions

- [GPT-5.4 nano](https://ai-tldr.dev/models/gpt-5-4-nano/) (17 March 2026)
- GPT-5 nano (7 August 2025) — this page

## FAQ

### What is GPT-5 nano?

GPT-5 nano is the smallest, fastest, and cheapest model in OpenAI's GPT-5 family, released on August 7, 2025. It is an API-only reasoning model built for high-volume, latency-sensitive tasks such as summarization and classification, where speed and cost matter more than maximum reasoning depth.

### How much does GPT-5 nano cost?

On the OpenAI API, GPT-5 nano costs $0.05 per million input tokens and $0.40 per million output tokens, with cached input priced at $0.005 per million tokens. That makes it OpenAI's cheapest GPT-5 model.

### What is the context window of GPT-5 nano?

GPT-5 nano has a 400,000-token context window and can generate up to 128,000 output tokens — the same context limit as the larger GPT-5 and GPT-5 mini models.

### Does GPT-5 nano support image input?

Yes. GPT-5 nano accepts both text and image input and returns text. Its knowledge cutoff is May 2024, and it is served via the OpenAI API as model id gpt-5-nano (snapshot gpt-5-nano-2025-08-07).

## Links

- [Introducing GPT-5 — OpenAI announcement](https://openai.com/index/introducing-gpt-5/)
- [GPT-5 nano — OpenAI API model page](https://developers.openai.com/api/docs/models/gpt-5-nano)
- [GPT-5 nano on OpenRouter](https://openrouter.ai/openai/gpt-5-nano)
- [GPT-5 nano — Artificial Analysis profile](https://artificialanalysis.ai/models/gpt-5-nano)

Source: AI/TLDR LLM registry, https://ai-tldr.dev/models/gpt-5-nano/