Model comparison

Fugu Max vs Gemini 3.5 Flash

Pricing, context window and real answers (September 2026)

Fugu Max (Sakana AI) and Gemini 3.5 Flash (Google), 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 Maxgoogle logoGemini 3.5 Flash
ProviderSakana AIGoogle
Input (per 1M tokens)¥357.4¥268.05
Output (per 1M tokens)¥1,072.2¥1,608.3
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥894¥1,072
Context window1,000,000 tokens1,048,576 tokens
Release date9/11/20265/19/2026
Input modalitiestext, image, filetext, image, video, file, audio
Throughput (p50)
Arena · overallUnranked#25 · ELO 1,478
Arena · JapaneseUnranked#19 · ELO 1,468
Arena · codingUnranked#55 · ELO 1,506

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

Which should you pick?

  • On price, Fugu Max: ¥1,072.2 per 1M output tokens, 33% less than Gemini 3.5 Flash.
  • For long documents, Gemini 3.5 Flash: a 1,048,576-token context window against 1,000,000 for Fugu Max.
  • 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

Gemini 3.5 Flash

There are **3** 'r's in the word "strawberry". Here is the step-by-step breakdown of how to count them: 1. **Break the word down into its individual letters:** * 1st letter: **s** * 2nd letter: **t** * 3rd letter: **r** (First 'r') * 4th letter: **a** * 5th letter: **w** * 6th letter: **b** * 7th letter: **e** * 8th letter: **r** (Second 'r') * 9th letter: **r** (Third 'r') * 10th letter: **y** 2. **Identify and count only the 'r's:** * s - t - **r** (1) - a - w - b - e - **r** (2) - **r** (3) - y By counting them as we go through the word, we find a total of **3** 'r's.
4.8s601 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

Gemini 3.5 Flash

### What is causing this error? The error `TypeError: Cannot read properties of undefined (reading 'map')` means that your `UserList` component is trying to call `.map()` on the `users` variable, but **`users` is currently `undefined`**. This usually happens for one of two reasons: 1. **The parent component forgot to pass the prop:** `<UserList />` was rendered without the `users` attribute. 2. **Asynchronous data fetching:** The parent component fetches the users from an API, but the API request hasn't finished yet when the component first renders, so `users` starts as `undefined`. --- ### How to fix it Here are the three best ways to fix this, depending on how you want your UI to beh…
11.2s1524 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

Gemini 3.5 Flash

Here is a review of your function, followed by two improved versions (one that keeps your structure but makes it Pythonic, and one production-ready version that uses industry best practices). --- ### Key Areas for Improvement 1. **Imports inside the function:** `import requests` and `import time` should be at the top of the file (PEP 8). Keeping them inside the function slows down execution if the function is called repeatedly. 2. **Bare `except:` clause:** Using `except:` without specifying an exception type is a major anti-pattern. It catches things you don't want to catch, like `KeyboardInterrupt` (Ctrl+C) or `SystemExit`. It should target `requests.RequestException`. 3. **Implicit `Tr…
19.7s2975 output tokens

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Frequently asked questions

Which is cheaper, Fugu Max or Gemini 3.5 Flash?
Per 1M output tokens, Fugu Max is ¥1,072.2 and Gemini 3.5 Flash is ¥1,608.3 on FastMetal (yen, before tax), so Fugu Max is cheaper.
How do the context windows of Fugu Max and Gemini 3.5 Flash compare?
Fugu Max takes 1,000,000 tokens; Gemini 3.5 Flash takes 1,048,576.
Can I use Fugu Max and Gemini 3.5 Flash with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-max" or "gemini-3.5-flash" 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 Gemini 3.5 Flash from the browser chat and the API. No monthly fee.

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