# GPT-5 mini

> OpenAI's fast, low-cost GPT-5 with a 400K context window and reasoning

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

## In short

GPT-5 mini is the mid-tier model in OpenAI's GPT-5 family, launched on August 7, 2025 alongside GPT-5 and GPT-5 nano. It has a 400K-token context window and costs $0.25 per million input tokens and $2.00 per million output tokens. You can use it through OpenAI and OpenRouter.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 400K (max output 128K) | [1] |
| Input price | $0.25 / 1M tokens (cached $0.025 / 1M tokens) | [2] |
| Output price | $2.00 / 1M tokens | [2] |
| Licence | Proprietary · API only | [1] |
| Released | 7 August 2025 | [3] |
| Knowledge cutoff | May 31, 2024 | [1] |

## Sources

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

## Overview

GPT-5 mini is the mid-tier model in OpenAI's GPT-5 family, launched on August 7, 2025 alongside GPT-5 and GPT-5 nano. OpenAI positions GPT-5 mini as a faster, more cost-efficient version of GPT-5 built for well-defined tasks and precise prompts, trading some of the flagship's depth for lower latency and a far cheaper price.

Like the rest of the GPT-5 line, GPT-5 mini is a reasoning model: it can spend extra tokens 'thinking' before it answers, and OpenAI's safety documentation refers to this variant as gpt-5-thinking-mini. It accepts text and image input and returns text, with a 400,000-token context window and up to 128,000 output tokens, making it suitable for long documents and code while keeping inference inexpensive.

GPT-5 mini is proprietary and closed-weight, available only through OpenAI's API (model id gpt-5-mini) and resellers such as OpenRouter. It is priced at $0.25 per million input tokens and $2.00 per million output tokens, with cached input at $0.025 per million. Its knowledge cutoff is May 31, 2024.

## Benchmarks

- HealthBench Hard: 40.3% ([source](https://cdn.openai.com/gpt-5-system-card.pdf))
- SimpleQA (accuracy, no web): 22% ([source](https://cdn.openai.com/gpt-5-system-card.pdf))

## Pricing

- Input: $0.25 / 1M tokens per 1M tokens
- Cached input: $0.025 / 1M tokens per 1M tokens
- Output: $2.00 / 1M tokens per 1M tokens

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

## Strengths

- Low price for a reasoning-capable model: $0.25 input / $2.00 output per million tokens, with cached input at $0.025
- Large 400K-token context window for long documents, transcripts, and codebases
- Up to 128K output tokens for long-form generation and detailed reasoning traces
- Adjustable reasoning effort, so you can dial cost and latency up or down per request
- Text plus image (vision) input through a single API model
- Available via OpenAI's Chat Completions and Responses APIs, plus OpenRouter

## Best for

- High-volume, well-defined tasks where a precise prompt matters more than maximum model depth
- Cost-sensitive classification, extraction, and summarization over long inputs
- Customer-support and assistant backends that need cheap reasoning at scale
- Document and codebase question-answering that benefits from the 400K context window
- Vision tasks such as reading screenshots, charts, or scanned pages from text-plus-image prompts
- A cheaper fallback or router tier behind a larger GPT-5 model for easy requests

## How to access

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

## GPT Mini versions

- [GPT-5.4 mini](https://ai-tldr.dev/models/gpt-5-4-mini/) (17 March 2026)
- GPT-5 mini (7 August 2025) — this page
- [GPT-4o mini](https://ai-tldr.dev/models/gpt-4o-mini/) (18 July 2024)

## FAQ

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

GPT-5 mini costs $0.25 per million input tokens and $2.00 per million output tokens through OpenAI's API, with cached input billed at $0.025 per million tokens.

### What is GPT-5 mini's context window?

GPT-5 mini has a 400,000-token context window and can return up to 128,000 output tokens per request.

### Is GPT-5 mini open source or downloadable?

No. GPT-5 mini is proprietary and closed-weight. It is only available through OpenAI's API (model id gpt-5-mini) and resellers such as OpenRouter; the weights cannot be downloaded or self-hosted.

### What can GPT-5 mini take as input?

GPT-5 mini accepts text and image (vision) input and returns text. It is a reasoning model with adjustable reasoning effort, and its knowledge cutoff is May 31, 2024.

## Links

- [OpenAI API docs — GPT-5 mini](https://developers.openai.com/api/docs/models/gpt-5-mini)
- [Introducing GPT-5 (OpenAI announcement)](https://openai.com/index/introducing-gpt-5/)
- [GPT-5 System Card (PDF)](https://cdn.openai.com/gpt-5-system-card.pdf)
- [GPT-5 mini on OpenRouter](https://openrouter.ai/openai/gpt-5-mini)
- [OpenAI API pricing](https://openai.com/api/pricing/)

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