GPT-4.1 Mini vs GPT-4.1 Nano
Pricing, context window and real answers (September 2026)
GPT-4.1 Mini (OpenAI) and GPT-4.1 Nano (OpenAI), compared as you can actually call them on FastMetal. Both are served from the same OpenAI-compatible endpoint and API key; switching is a change to the model string.
Specs and pricing
 GPT-4.1 Mini | GPT-4.1 Nano | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input (per 1M tokens) | ¥71.48 | ¥17.87 |
| Output (per 1M tokens) | ¥285.92 | ¥71.48 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥214 | ¥54 |
| Context window | 1,047,576 tokens | 1,047,576 tokens |
| Release date | 4/14/2025 | 4/14/2025 |
| Input modalities | image, text, file | image, text, file |
| Throughput (p50) | — | — |
| Arena · overall | #172 · ELO 1,383 | #243 · ELO 1,322 |
| Arena · Japanese | #135 · ELO 1,330 | #195 · ELO 1,234 |
| Arena · coding | #164 · ELO 1,433 | #226 · ELO 1,374 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, GPT-4.1 Nano: ¥71.48 per 1M output tokens, 75% less than GPT-4.1 Mini.
- On the Overall arena board, GPT-4.1 Mini ranks higher (#172; GPT-4.1 Nano is #243).
- On the Japanese arena board, GPT-4.1 Mini ranks higher (#135; GPT-4.1 Nano is #195).
- On the Coding arena board, GPT-4.1 Mini ranks higher (#164; GPT-4.1 Nano is #226).
- If in doubt, try both on the same key. Switching is a change to the model string, and each is billed at its own rate.
Real answers to the same prompts
Exactly what the FastMetal gateway returned, side by side. Not benchmark scores: actual output.
Count the number of 'r's in 'strawberry'
Count the number of 'r's in 'strawberry'. Explain your reasoning step by step.
GPT-4.1 Mini
Let's count the number of 'r's in the word "strawberry" step by step:
1. Write down the word: s t r a w b e r r y
2. Look at each letter and check if it is 'r':
- s → not 'r'
- t → not 'r'
- r → yes, 1st 'r'
- a → not 'r'
- w → not 'r'
- b → not 'r'
- e → not 'r'
- r → yes, 2nd 'r'
- r → yes, 3rd 'r'
- y → not 'r'
3. Total number of 'r's found: 3
**Answer:** There are 3 'r's in the word "strawberry".
2.0s176 output tokens
GPT-4.1 Nano
Let's analyze the word "strawberry" step by step to count the number of 'r's.
1. Write down the word: **strawberry**
2. Examine each letter one by one:
- s: no
- t: no
- r: yes (first 'r')
- a: no
- w: no
- b: no
- e: no
- r: yes (second 'r')
- r: yes (third 'r')
- y: no
3. Counting the 'r's found:
- First 'r' (at position 3)
- Second 'r' (at position 8)
- Third 'r' (at position 9)
So, there are **3** 'r's in "strawberry."
**Final answer: 3**
2.0s183 output tokens
Debug This Error
I'm getting the following error in my Node.js application: TypeError: Cannot read properties of undefined (reading 'map') at UserList (/app/components/UserList.js:12:25) at renderWithHooks (/app/node_modules/rea…
GPT-4.1 Mini
The error **"TypeError: Cannot read properties of undefined (reading 'map')"** means that the `users` prop passed to your `UserList` component is `undefined` at the time the component tries to render, so calling `.map()` on it throws an error.
### What's causing the error?
- Your component expects `users` to be an array, but for some reason it is `undefined` when the component renders.
- This could happen if:
- The parent component that passes the `users` prop did not pass it or passed `undefined`.
- The data is being fetched asynchronously and hasn't arrived yet.
- The default prop is missing or no default fallback is handled.
### How to fix it?
You want to ensure `users` is alway…
8.1s465 output tokens
GPT-4.1 Nano
The error:
```
TypeError: Cannot read properties of undefined (reading 'map')
```
indicates that `users` is `undefined` at the time your `UserList` component is rendering, and you're trying to call `map` on it.
### Why is this happening?
In React, if a prop (`users` in this case) is not provided or is undefined, trying to do `users.map(...)` causes this error. This can happen if:
- The parent component does not pass `users`.
- `users` might be `null` or `undefined` initially, especially if data fetching is involved.
### How to fix it
**Option 1: Provide a default value for `users`**
Ensure that `users` defaults to an empty array if it is not provided:
```jsx
function UserList({ users…
4.3s514 output tokens
Code Review
Please review the following Python function and suggest improvements for readability, performance, and best practices: def get_data(url, retries=3): import requests import time for i in range(retries):…
GPT-4.1 Mini
Your function is functional but can be improved for readability, performance, and best practices. Here are some suggestions and an improved version of your function:
### Issues and improvements
1. **Imports**: Import at the top of the file rather than inside the function.
2. **Catch specific exceptions**: Avoid bare `except:` clauses. Catch specific exceptions like `requests.RequestException` or `json.decoder.JSONDecodeError`.
3. **Use list comprehension**: Instead of a loop with `append()`, use list comprehension for clarity and conciseness.
4. **Check boolean conditions directly**: Instead of `item["active"] == True`, just use `item["active"]`.
5. **Avoid sleeping after last retry**: No…
5.6s690 output tokens
GPT-4.1 Nano
Here's a review and an improved version of your function:
### Key improvements:
1. **Move imports to the top**: Imports should generally be at the top of the file, not inside functions.
2. **Specify exception types**: Catch specific exceptions rather than a generic `except`.
3. **Use context managers if needed**: Not necessary here, but good to consider.
4. **Avoid repeated code**: The sleep statement is the same whether there is a request exception or a non-200 status.
5. **Simplify filtering**: Use list comprehensions for clarity.
6. **Improve variable names**: For readability.
7. **Add optional headers or parameters** if needed (not required here).
8. **Optional:** Add more descriptive e…
3.4s391 output tokens
Frequently asked questions
- Which is cheaper, GPT-4.1 Mini or GPT-4.1 Nano?
- Per 1M output tokens, GPT-4.1 Mini is ¥285.92 and GPT-4.1 Nano is ¥71.48 on FastMetal (yen, before tax), so GPT-4.1 Nano is cheaper.
- How do the context windows of GPT-4.1 Mini and GPT-4.1 Nano compare?
- GPT-4.1 Mini takes 1,047,576 tokens; GPT-4.1 Nano takes 1,047,576.
- Which ranks higher, GPT-4.1 Mini or GPT-4.1 Nano?
- GPT-4.1 Mini ranks higher on the public arena (GPT-4.1 Mini #135, GPT-4.1 Nano #195). Ranks move as the leaderboard updates.
- Can I use GPT-4.1 Mini and GPT-4.1 Nano with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-4.1-mini" or "gpt-4.1-nano" as the model. Each is billed at its own rate from the same prepaid balance.
Try both on one API key
Create an account and add credit to call GPT-4.1 Mini and GPT-4.1 Nano from the browser chat and the API. No monthly fee.