Hy4 vs Solar Mini 4
Pricing, context window and real answers (November 2026)
Hy4 (Tencent) 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
 Hy4 | Solar Mini 4 | |
|---|---|---|
| Provider | Tencent | Upstage |
| Input (per 1M tokens) | $0.8799 | $0.055 |
| Output (per 1M tokens) | $2.64 | $0.22 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | $2.20 | $0.165 |
| Context window | 1,000,000 tokens | 524,288 tokens |
| Release date | 11/4/2026 | 9/23/2026 |
| Input modalities | text | text |
| Throughput (p50) | — | 90 tokens/s (n=28) |
| Arena · overall | Unranked | Unranked |
| Arena · Japanese | Unranked | Unranked |
| Arena · coding | Unranked | Unranked |
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, Solar Mini 4: $0.22 per 1M output tokens, 92% less than Hy4.
- For long documents, Hy4: 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.
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
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…
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
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):…
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
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
Frequently asked questions
- Which is cheaper, Hy4 or Solar Mini 4?
- Per 1M output tokens, Hy4 is $2.64 and Solar Mini 4 is $0.22 on FastMetal (US dollars, before tax), so Solar Mini 4 is cheaper.
- How do the context windows of Hy4 and Solar Mini 4 compare?
- Hy4 takes 1,000,000 tokens; Solar Mini 4 takes 524,288.
- Can I use Hy4 and Solar Mini 4 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "hy4" 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 Hy4 and Solar Mini 4 from the browser chat and the API. No monthly fee.