Fugu Max vs Kimi K3
Pricing, context window and real answers (September 2026)
Fugu Max (Sakana AI) and Kimi K3 (Moonshot), 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 Max |  Kimi K3 | |
|---|---|---|
| Provider | Sakana AI | Moonshot |
| Input (per 1M tokens) | ¥357.4 | ¥504 |
| Output (per 1M tokens) | ¥1,072.2 | ¥2,520 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥894 | ¥1,764 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Release date | 9/11/2026 | 7/16/2026 |
| Input modalities | text, image, file | text, image |
| Throughput (p50) | — | — |
| Arena · overall | Unranked | #17 · ELO 1,485 |
| Arena · Japanese | Unranked | #2 · ELO 1,511 |
| Arena · coding | Unranked | #7 · ELO 1,538 |
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, 57% less than Kimi K3.
- For long documents, Kimi K3: 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
Kimi K3
# Counting the 'r's in "strawberry"
**Step 1: Write out each letter with its position**
| Position | Letter |
|----------|--------|
| 1 | s |
| 2 | t |
| 3 | **r** ✓ |
| 4 | a |
| 5 | w |
| 6 | b |
| 7 | e |
| 8 | **r** ✓ |
| 9 | **r** ✓ |
| 10 | y |
**Step 2: Identify each 'r'**
- Position 3: the 'r' in "st**r**"
- Position 8: the first 'r' in "be**r**ry"
- Position 9: the second 'r' in "ber**r**y"
**Step 3: Verify by splitting the word**
"Strawberry" = "straw" + "berry"
- "straw" contains **1** r
- "berry" contains **2** r's
**Answer: There are 3 r's in "strawberry."** 🍓
12.2s594 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
Kimi K3
## What's causing it
The error means `users` is `undefined` when the component renders — `.map()` only exists on arrays, so calling it on `undefined` throws. Your component code is fine; the problem is **upstream**: whatever renders `<UserList />` isn't passing a valid array.
The most common culprit is **async data fetching with uninitialized state** in the parent:
```jsx
function App() {
const [users, setUsers] = useState(); // ← undefined!
useEffect(() => {
fetch('/api/users')
.then(res => res.json())
.then(setUsers);
}, []);
return <UserList users={users} />; // undefined on first render
}
```
The component renders *before* the fetch resolves, so `users` is `…
47.5s1756 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
Kimi K3
This works, but there are several issues worth addressing. Here's a breakdown, followed by an improved version.
## Issues
### Correctness & best practices
1. **Bare `except:`** — catches *everything*, including `KeyboardInterrupt` and programming bugs like `KeyError` on a malformed item (which then get pointlessly retried). Catch `requests.RequestException` specifically.
2. **Silent failures** — errors are swallowed with no logging, and returning `[]` makes "API is down" indistinguishable from "no active items." At minimum, log; ideally, raise after the final attempt.
3. **Retrying non-retryable errors** — a 400/401/404 will never succeed on retry, but the code sleeps and retries anyway. O…
57.6s8060 output tokens
Frequently asked questions
- Which is cheaper, Fugu Max or Kimi K3?
- Per 1M output tokens, Fugu Max is ¥1,072.2 and Kimi K3 is ¥2,520 on FastMetal (yen, before tax), so Fugu Max is cheaper.
- How do the context windows of Fugu Max and Kimi K3 compare?
- Fugu Max takes 1,000,000 tokens; Kimi K3 takes 1,048,576.
- Can I use Fugu Max and Kimi K3 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-max" or "kimi-k3" 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 Kimi K3 from the browser chat and the API. No monthly fee.