DeepSeek V4.1 Flash vs Hy4
Pricing, context window and real answers (November 2026)
DeepSeek V4.1 Flash (DeepSeek) 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
 DeepSeek V4.1 Flash |  Hy4 | |
|---|---|---|
| Provider | DeepSeek | Tencent |
| Input (per 1M tokens) | $0.211 | $0.8799 |
| Output (per 1M tokens) | $0.633 | $2.64 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | $0.5275 | $2.20 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Release date | 9/10/2026 | 11/4/2026 |
| Input modalities | text, image | text |
| Throughput (p50) | 221 tokens/s (n=28) | — |
| Arena · overall | #35 · ELO 1,476 | Unranked |
| Arena · Japanese | #40 · ELO 1,452 | Unranked |
| Arena · coding | #31 · ELO 1,523 | 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, DeepSeek V4.1 Flash: $0.633 per 1M output tokens, 76% less than Hy4.
- For long documents, DeepSeek V4.1 Flash: a 1,048,576-token context window against 1,000,000 for Hy4.
- 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.
DeepSeek V4.1 Flash
The word **“strawberry”** has **3** letter **“r”**s.
Step-by-step:
1. Spell it out: **s t r a w b e r r y**
2. Find each **r**:
- Position 3: **r** in “str”
- Position 8: first **r** in “berry”
- Position 9: second **r** in “berry”
3. Total: **3**
**Answer: 3**
7.5s226 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…
DeepSeek V4.1 Flash
The error means that `users` is `undefined` when `UserList` renders, so JavaScript cannot call `.map()` on it.
Your component expects a `users` prop:
```jsx
function UserList({ users }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
But it is being rendered without `users`, or `users` has not loaded yet.
Common causes:
1. Parent renders it without the prop:
```jsx
<UserList />
```
instead of:
```jsx
<UserList users={users} />
```
2. The prop name is different:
```jsx
<UserList userList={users} />
```
3. The data is fetched asynchronously and is initially `undefined`:
```jsx
const [users, setUsers] = useState();
useEffect(…
16.0s945 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):…
DeepSeek V4.1 Flash
Here are the main improvements:
- Move imports to module level.
- Avoid bare `except`; catch specific exceptions.
- Use a `requests.Session` for connection reuse.
- Retry only transient network/HTTP failures, not all errors.
- Use exponential backoff and don’t sleep after the final attempt.
- Use a list comprehension for readability/performance.
- Add type hints, logging, constants, and basic JSON validation.
- Avoid `== True`; use `is True` or a truthy check depending on API contract.
Example refactor:
```python
from __future__ import annotations
import logging
import time
from typing import Any
import requests
logger = logging.getLogger(__name__)
TIMEOUT = (3.05, 10) # connect time…
31.5s5142 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
Frequently asked questions
- Which is cheaper, DeepSeek V4.1 Flash or Hy4?
- Per 1M output tokens, DeepSeek V4.1 Flash is $0.633 and Hy4 is $2.64 on FastMetal (US dollars, before tax), so DeepSeek V4.1 Flash is cheaper.
- How do the context windows of DeepSeek V4.1 Flash and Hy4 compare?
- DeepSeek V4.1 Flash takes 1,048,576 tokens; Hy4 takes 1,000,000.
- Can I use DeepSeek V4.1 Flash and Hy4 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "deepseek-v4.1-flash" 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 DeepSeek V4.1 Flash and Hy4 from the browser chat and the API. No monthly fee.