Model comparison

Fugu Max vs gpt-oss-20b

Pricing, context window and real answers (September 2026)

Fugu Max (Sakana AI) and gpt-oss-20b (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

Fugu Maxopenai logogpt-oss-20b
ProviderSakana AIOpenAI
Input (per 1M tokens)¥357.4¥5.36
Output (per 1M tokens)¥1,072.2¥25.02
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥894¥18
Context window1,000,000 tokens131,072 tokens
Release date9/11/20268/5/2025
Input modalitiestext, image, filetext
Throughput (p50)
Arena · overallUnranked#252 · ELO 1,317
Arena · JapaneseUnranked#179 · ELO 1,256
Arena · codingUnranked#232 · ELO 1,369

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

Which should you pick?

  • On price, gpt-oss-20b: ¥25.02 per 1M output tokens, 98% less than Fugu Max.
  • For long documents, Fugu Max: a 1,000,000-token context window against 131,072 for gpt-oss-20b.
  • 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

gpt-oss-20b

**Count of ‘r’ in “strawberry”: 3** --- ### Step‑by‑step reasoning 1. **Write out the word in individual letters** ``` s t r a w b e r r y ``` 2. **Identify each ‘r’** - The first ‘r’: appears after the “t” → **r** - The second ‘r’: appears in the part “berry” → **r** - The third ‘r’: the next letter after that → **r** 3. **Verify there are no more letters left** The remaining letters are “b”, “e”, “y”, none of which are “r”. 4. **Count the identified ‘r’s** 1 (first) + 1 (second) + 1 (third) = **3** --- ### Quick recap - Word: **strawberry** - Letters containing “r”: positions 3, 8, and 9. - Total count: **3**.
11.6s371 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

gpt-oss-20b

### Why does the error happen? `users.map(...)` can only run when **`users` is an array**. The stack trace shows that the crash happens on line 12 of `UserList.js`, which is the exact spot where the code tries to call `.map`. The value that is being passed to `UserList` (or the initial value that the parent creates) is **`undefined`** (or it could be `null`/`{}`). When JavaScript tries to read `users.map`, it throws: ``` TypeError: Cannot read properties of undefined (reading 'map') ``` Typical reasons for this are: 1. The parent component **didn’t pass the `users` prop** at all. 2. The parent passed it but the value was **`undefined` / `null`** because data hasn’t been loaded ye…
11.4s1303 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

gpt-oss-20b

Below is a quick “code‑review” style list that touches the three axes you asked for – **readability**, **performance**, and **best practices**. After the bullet‑list I’ll paste a refactored version that incorporates the most common fixes. --- ## 1. Readability | Issue | Why it hurts | Quick fix | |-------|--------------|-----------| | **Imports inside the function** | Every call recompiles the import tables and makes the module’s top‑level slower. | Move `import requests` and `import time` to the module’s global header. | | **Bare `except:`** | Catches *everything* (KeyboardInterrupt, SystemExit, MemoryError, etc.) and swallows useful tracebacks. | Catch only the expected network-relate…
24.6s2267 output tokens

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Frequently asked questions

Which is cheaper, Fugu Max or gpt-oss-20b?
Per 1M output tokens, Fugu Max is ¥1,072.2 and gpt-oss-20b is ¥25.02 on FastMetal (yen, before tax), so gpt-oss-20b is cheaper.
How do the context windows of Fugu Max and gpt-oss-20b compare?
Fugu Max takes 1,000,000 tokens; gpt-oss-20b takes 131,072.
Can I use Fugu Max and gpt-oss-20b with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-max" or "gpt-oss-20b" 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 gpt-oss-20b from the browser chat and the API. No monthly fee.

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