Model comparison

GPT-4o-mini vs GPT-6 Astra

Pricing, context window and real answers (September 2026)

GPT-4o-mini (OpenAI) and GPT-6 Astra (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

openai logoGPT-4o-miniopenai logoGPT-6 Astra
ProviderOpenAIOpenAI
Input (per 1M tokens)¥26.81¥1,717.72
Output (per 1M tokens)¥107.22¥8,588.62
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥80¥6,012
Context window128,000 tokens1,050,000 tokens
Release date7/18/20249/4/2026
Input modalitiestext, image, filefile, image, text
Throughput (p50)
Arena · overall#251 · ELO 1,318#24 · ELO 1,480
Arena · Japanese#187 · ELO 1,250Unranked
Arena · coding#259 · ELO 1,348#6 · ELO 1,543

Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.

Which should you pick?

  • On price, GPT-4o-mini: ¥107.22 per 1M output tokens, 99% less than GPT-6 Astra.
  • On the Overall arena board, GPT-6 Astra ranks higher (#24; GPT-4o-mini is #251).
  • On the Coding arena board, GPT-6 Astra ranks higher (#6; GPT-4o-mini is #259).
  • For long documents, GPT-6 Astra: a 1,050,000-token context window against 128,000 for GPT-4o-mini.
  • 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-4o-mini

To count the number of 'r's in the word "strawberry," we can follow these steps: 1. **Identify the word**: We have the word "strawberry." 2. **Break down the letters**: Let's write out the letters in the word: - s - t - r - a - w - b - e - r - r - y 3. **Locate the 'r's**: Now, we need to look for the letter 'r' among these letters. - In the list of letters, we can see: - The first 'r' is in the 3rd position. - The second 'r' is in the 8th position. - The third 'r' is in the 9th position. 4. **Count the occurrences**: We check each position we identified: - There are three occurrences of 'r' in the word "strawberry." 5. **Conclusion**:…
2.1s239 output tokens

GPT-6 Astra

“strawberry” is spelled **s-t-r-a-w-b-e-r-r-y**. The letter **r** appears in positions **3, 8, and 9**, so there are **3 r’s**.
3.8s85 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-4o-mini

The error you're encountering, `TypeError: Cannot read properties of undefined (reading 'map')`, indicates that the `users` prop is `undefined` when you try to call the `map` method on it. In your `UserList` component, you're attempting to use `users.map(...)`, but if the `users` prop is not provided or is `undefined`, this will throw an error. ### Fixing the Error 1. **Default Props**: You can set a default value for the `users` prop to prevent the error when it is `undefined`. ```jsx function UserList({ users = [] }) { // Default to an empty array return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ```…
5.0s511 output tokens

GPT-6 Astra

The error means **`users` is `undefined` when React renders `UserList`**, so calling `users.map(...)` fails. This commonly happens when the parent doesn’t pass the prop or when data hasn’t finished loading. ### 1. Default `users` to an empty array If an absent prop should mean “no users,” use a default value: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => ( <li key={user.id}>{user.name}</li> ))} </ul> ); } ``` This handles a missing or `undefined` prop, but **not `null` or other non-array values**. ### 2. Check where the prop comes from Make sure the parent passes an array. For data loaded asynchronously, initialize state to…
6.7s380 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-4o-mini

Your Python function, `get_data`, essentially performs a GET request, handles retries on failure, and processes the response JSON to return a filtered list of dictionaries. Below, I've highlighted several improvements regarding readability, performance, and best practices: 1. **Avoid blanket exceptions**: It’s best practice to specify which exceptions you expect, allowing for better debugging and error handling. 2. **Use `requests` built-in exception handling**: Handle specific requests exceptions, such as `requests.exceptions.RequestException`. 3. **Improve condition checks**: Check for `item['active']` directly instead of comparing to `True`, which is more Pythonic. 4. **Use `time.sl…
8.8s628 output tokens

GPT-6 Astra

The function is compact, but its biggest issue is that **all failures silently become `[]`**, making an unavailable API indistinguishable from a successful response with no active items. ### Suggested improvements - **Move imports to module scope** for clarity and conventional organization. - **Avoid bare `except:`.** It catches everything, including `KeyboardInterrupt`, and hides bugs such as missing dictionary keys. - **Retry only transient failures**, such as connection errors, timeouts, rate limiting, and selected server errors. Retrying a `401` or `404` usually won’t help. - **Don’t sleep after the final failed attempt.** Use exponential backoff rather than a fixed delay. - **Use desc…
19.2s965 output tokens

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Frequently asked questions

Which is cheaper, GPT-4o-mini or GPT-6 Astra?
Per 1M output tokens, GPT-4o-mini is ¥107.22 and GPT-6 Astra is ¥8,588.62 on FastMetal (yen, before tax), so GPT-4o-mini is cheaper.
How do the context windows of GPT-4o-mini and GPT-6 Astra compare?
GPT-4o-mini takes 128,000 tokens; GPT-6 Astra takes 1,050,000.
Which ranks higher, GPT-4o-mini or GPT-6 Astra?
GPT-6 Astra ranks higher on the public arena (GPT-4o-mini #187, GPT-6 Astra #24). Ranks move as the leaderboard updates.
Can I use GPT-4o-mini and GPT-6 Astra with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-4o-mini" or "gpt-6-astra" 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-4o-mini and GPT-6 Astra from the browser chat and the API. No monthly fee.

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