Model comparison

GPT-4.1 Nano vs Inkling

Pricing, context window and real answers (September 2026)

GPT-4.1 Nano (OpenAI) and Inkling (Thinking Machines), 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

openai logoGPT-4.1 NanoInkling
ProviderOpenAIThinking Machines
Input (per 1M tokens)¥17.87¥178.7
Output (per 1M tokens)¥71.48¥723.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥54¥541
Context window1,047,576 tokens524,288 tokens
Release date4/14/20257/17/2026
Input modalitiesimage, text, filetext, image, audio
Throughput (p50)
Arena · overall#243 · ELO 1,322#85 · ELO 1,440
Arena · Japanese#195 · ELO 1,234#63 · ELO 1,415
Arena · coding#226 · ELO 1,374#78 · ELO 1,492

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, 90% less than Inkling.
  • On the Overall arena board, Inkling ranks higher (#85; GPT-4.1 Nano is #243).
  • On the Japanese arena board, Inkling ranks higher (#63; GPT-4.1 Nano is #195).
  • On the Coding arena board, Inkling ranks higher (#78; GPT-4.1 Nano is #226).
  • For long documents, GPT-4.1 Nano: a 1,047,576-token context window against 524,288 for Inkling.
  • 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 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

Inkling

Let's break down the word **"strawberry"** letter by letter: 1. **s** 2. **t** 3. **r** ← (1st 'r') 4. **a** 5. **w** 6. **b** 7. **e** 8. **r** ← (2nd 'r') 9. **r** ← (3rd 'r') 10. **y** So the spelling is: s-t-**r**-a-w-b-e-**r**-**r**-y Counting them up: - One 'r' in "str" (the 3rd letter) - Two 'r's in "berry" (the 8th and 9th letters) **Total: 3 'r's** in "strawberry".**
2.4s417 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 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

Inkling

The error occurs because `users` is `undefined` when `UserList` renders, so `users.map` fails. This usually happens when: - The parent doesn't pass the prop (`<UserList />` instead of `<UserList users={...} />`) - Data is still loading (e.g., API hasn't returned yet) ## Quick Fix Provide a default empty array so `.map` always has an array to work with: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Alternatively, guard against undefined explicitly: ```jsx function UserList({ users }) { if (!users) return null; // or a loading state return ( <ul> {users.map(user => <li key={…
4.9s585 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 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

Inkling

Here is a review with an improved version followed by explanations. ### Issues in the original - **Imports inside the function**: Re-importing on every call is inefficient. - **Bare `except:`**: Catches `SystemExit`, `KeyboardInterrupt`, etc. - **Silent failures**: No logging; errors disappear. - **Magic numbers**: `10`, `2`, `200` are hard-coded. - **Data validation missing**: Assumes `data` is a list and every item has `"active"`, `"name"`, and `"id"` (will crash with `KeyError`). - **Performance**: Uses `.append()` in a loop instead of a list comprehension. - **Ambiguous return**: `[]` means both "success with no results" and "total failure". ### Improved version ```python import loggi…
54.1s5649 output tokens

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Frequently asked questions

Which is cheaper, GPT-4.1 Nano or Inkling?
Per 1M output tokens, GPT-4.1 Nano is ¥71.48 and Inkling is ¥723.74 on FastMetal (yen, before tax), so GPT-4.1 Nano is cheaper.
How do the context windows of GPT-4.1 Nano and Inkling compare?
GPT-4.1 Nano takes 1,047,576 tokens; Inkling takes 524,288.
Which ranks higher, GPT-4.1 Nano or Inkling?
Inkling ranks higher on the public arena (GPT-4.1 Nano #195, Inkling #63). Ranks move as the leaderboard updates.
Can I use GPT-4.1 Nano and Inkling with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-4.1-nano" or "inkling" 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 Nano and Inkling from the browser chat and the API. No monthly fee.

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