Model comparison

Fugu Max vs Solar Mini 4

Pricing, context window and real answers (September 2026)

Fugu Max (Sakana AI) 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

Fugu MaxSolar Mini 4
ProviderSakana AIUpstage
Input (per 1M tokens)¥357.4¥8.94
Output (per 1M tokens)¥1,072.2¥35.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥894¥27
Context window1,000,000 tokens524,288 tokens
Release date9/11/20269/23/2026
Input modalitiestext, image, filetext
Throughput (p50)——
Arena · overallUnrankedUnranked
Arena · JapaneseUnrankedUnranked
Arena · codingUnrankedUnranked

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, 97% less than Fugu Max.
  • For long documents, Fugu Max: a 1,000,000-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.

Fugu Max

The word **“strawberry”** has **3** letters **“r”**. Step by step: 1. Write the word: **s t r a w b e r r y** 2. Check each letter: - s — no - t — no - **r** — yes, 1st - a — no - w — no - b — no - e — no - **r** — yes, 2nd - **r** — yes, 3rd - y — no So, the total number of **‘r’s** in **“strawberry”** is **3**.
3.7s261 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…

Fugu Max

The error means `users` is `undefined` when `UserList` renders, so `users.map(...)` throws: ```js function UserList({ users }) { // if `users` is not passed, this is undefined return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Common causes: 1. Parent renders `<UserList />` without the `users` prop. 2. State is initialized as `undefined`: ```js const [users, setUsers] = useState(); ``` 3. Async data hasn’t loaded yet, but the component already renders. 4. The API returned something unexpected, e.g. `undefined`, an object, or an error response. ## Fixes ### 1. Default the prop to an empty array ```jsx function UserList({ use…
10.6s1293 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):…

Fugu Max

Here’s a review with concrete improvements. ## Main issues 1. **Bare `except:`** - Catches everything, including `KeyboardInterrupt`, `SystemExit`, and programming errors. - Catch `requests.RequestException` instead, plus `ValueError` for JSON parsing if needed. 2. **Retries everything, including non-retryable errors** - A `404` or `401` will be retried even though retrying will not help. - Retry only transient failures: network errors, `429`, and `5xx`. 3. **Fixed 2-second sleep** - No exponential backoff. Repeated retries can hammer the server. - Use exponential backoff, optionally with jitter. 4. **Silent failure** - Returning `[]` after all retries makes it hard…
24.7s3795 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, Fugu Max or Solar Mini 4?
Per 1M output tokens, Fugu Max is ¥1,072.2 and Solar Mini 4 is ¥35.74 on FastMetal (yen, before tax), so Solar Mini 4 is cheaper.
How do the context windows of Fugu Max and Solar Mini 4 compare?
Fugu Max takes 1,000,000 tokens; Solar Mini 4 takes 524,288.
Can I use Fugu Max and Solar Mini 4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-max" 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 Fugu Max and Solar Mini 4 from the browser chat and the API. No monthly fee.

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