Model comparison

GPT-6 Astra vs Solar Mini 4

Pricing, context window and real answers (September 2026)

GPT-6 Astra (OpenAI) and Solar Mini 4 (Upstage), 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-6 AstraSolar Mini 4
ProviderOpenAIUpstage
Input (per 1M tokens)¥1,787¥8.94
Output (per 1M tokens)¥8,935¥35.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥6,255¥27
Context window1,050,000 tokens524,288 tokens
Release date9/4/20269/23/2026
Input modalitiesfile, image, texttext
Throughput (p50)——
Arena · overall#24 · ELO 1,480Unranked
Arena · JapaneseUnrankedUnranked
Arena · coding#6 · ELO 1,543Unranked

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

Which should you pick?

  • On price, Solar Mini 4: ¥35.74 per 1M output tokens, 100% less than GPT-6 Astra.
  • For long documents, GPT-6 Astra: a 1,050,000-token context window against 524,288 for Solar Mini 4.
  • 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-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

Solar Mini 4

Sure! Let’s count the letter **'r'** in the word **'strawberry'** step by step. **Step 1: Write out the word and its letters** `s t r a w b e r r y` **Step 2: Go through each letter one by one and check if it is 'r'** 1. `s` → not 'r' 2. `t` → not 'r' 3. `r` → **yes** (1st 'r') 4. `a` → not 'r' 5. `w` → not 'r' 6. `b` → not 'r' 7. `e` → not 'r' 8. `r` → **yes** (2nd 'r') 9. `r` → **yes** (3rd 'r') 10. `y` → not 'r' **Step 3: Tally the total** Total 'r' count = 3 **Final answer:** There are **3** letter 'r's in the word **'strawberry'**.
2.5s239 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-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

Solar Mini 4

This error occurs because the `users` prop being passed to your `UserList` component is `undefined` (or the component is rendered without that prop), and your code tries to call `.map()` on it. ### 🔍 Why this happens In JavaScript, `undefined.map` is not a function, so calling it throws: ``` TypeError: Cannot read properties of undefined (reading 'map') ``` This commonly happens when: - The parent component doesn't pass the `users` prop at all - The parent passes `users` as `undefined`, `null`, or a non-array value (like a promise, object, or string) - Data hasn't finished loading yet (e.g., fetched from an API asynchronously) ### ✅ How to fix it The most robust solution is to provide a…
9.2s701 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-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

Solar Mini 4

Here’s a reviewed version of your function, followed by a breakdown of the improvements: ```python import time import requests from requests.adapters import HTTPAdapter from urllib3.util.retry import Retry def get_data(url: str, retries: int = 3) -> list[dict]: """ Fetch JSON from a URL and return a list of active items with name/id. Args: url: The endpoint to request. retries: Number of retry attempts on failure. Returns: A list of dicts matching {'name': str, 'id': any} for active items. """ if retries < 1: raise ValueError("retries must be at least 1") session = requests.Session() retry_strategy = Retry( total=re…
10.8s1278 output tokens

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Frequently asked questions

Which is cheaper, GPT-6 Astra or Solar Mini 4?
Per 1M output tokens, GPT-6 Astra is ¥8,935 and Solar Mini 4 is ¥35.74 on FastMetal (yen, before tax), so Solar Mini 4 is cheaper.
How do the context windows of GPT-6 Astra and Solar Mini 4 compare?
GPT-6 Astra takes 1,050,000 tokens; Solar Mini 4 takes 524,288.
Can I use GPT-6 Astra and Solar Mini 4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-astra" or "solar-mini4" 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-6 Astra and Solar Mini 4 from the browser chat and the API. No monthly fee.

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