Model comparison

Fugu Max vs Hy4

Pricing, context window and real answers (November 2026)

Fugu Max (Sakana AI) and Hy4 (Tencent), 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 Maxtencent logoHy4
ProviderSakana AITencent
Input (per 1M tokens)$2.20$0.8799
Output (per 1M tokens)$6.60$2.64
Typical cost (1,000 in + 500 out tokens × 1,000 calls)$5.50$2.20
Context window1,000,000 tokens1,000,000 tokens
Release date9/11/202611/4/2026
Input modalitiestext, image, filetext
Throughput (p50)1496 tokens/s (n=27)—
Arena · overallUnrankedUnranked
Arena · JapaneseUnrankedUnranked
Arena · codingUnrankedUnranked

Prices are FastMetal's rates, before tax.

Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-28; category names mapped and ratings rounded by FastMetal.

Which should you pick?

  • On price, Hy4: $2.64 per 1M output tokens, 60% less than 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

Hy4

The word **“strawberry”** is spelled: **s t r a w b e r r y** Step by step: 1. Check each letter: s, t, **r**, a, w, b, e, **r**, **r**, y 2. Mark the **r**’s: one after **t**, and two near the end before **y**. 3. Count them: 1 + 1 + 1 = **3** So, there are **3** ‘r’s in **“strawberry”**.
4.2s343 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

Hy4

The error is caused by this line: ```js {users.map(user => <li key={user.id}>{user.name}</li>)} ``` At render time, `users` is `undefined`. Since `.map()` only exists on arrays, JavaScript tries to read `map` from `undefined` and throws: ```txt Cannot read properties of undefined (reading 'map') ``` Even though this is in a Node.js app, this specific error is happening during React rendering, likely server-side rendering or a Node-based build/render process. Common causes: 1. The parent component is not passing `users`. 2. The prop name is misspelled. 3. `users` comes from async data and is `undefined` on the first render. 4. Your API returns something like `{ users: [...] }`, but you…
20.3s1951 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

Hy4

Here are the main improvement areas, followed by a possible rewrite. ## Key issues ### Readability / style - Move imports to the top of the module. - Use descriptive names: `response` instead of `r`, `attempt` instead of `i`. - `if item["active"] == True:` should be `if item.get("active") is True:` or simply `if item.get("active"):`, depending on intent. - The filtering loop can be a list comprehension. - Add type hints and a docstring. ### Performance - Repeated imports are cached by Python, so not a major cost, but top-level imports are cleaner. - Avoid sleeping after the final failed attempt. - Use `requests.Session` for connection pooling if this function may be called repeatedly or i…
110.2s10761 output tokens

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Frequently asked questions

Which is cheaper, Fugu Max or Hy4?
Per 1M output tokens, Fugu Max is $6.60 and Hy4 is $2.64 on FastMetal (US dollars, before tax), so Hy4 is cheaper.
How do the context windows of Fugu Max and Hy4 compare?
Fugu Max takes 1,000,000 tokens; Hy4 takes 1,000,000.
Can I use Fugu Max and Hy4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "fugu-max" or "hy4" 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 Hy4 from the browser chat and the API. No monthly fee.

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