DeepSeek V4 Flash vs Gemini 3.7 Flash
Pricing, context window and real answers (August 2026)
DeepSeek V4 Flash (DeepSeek) and Gemini 3.7 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
 DeepSeek V4 Flash |  Gemini 3.7 Flash | |
|---|---|---|
| Provider | DeepSeek | |
| Input (per 1M tokens) | ¥16.08 | ¥134.03 |
| Output (per 1M tokens) | ¥32.17 | ¥670.13 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥32 | ¥469 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Release date | 4/24/2026 | 8/13/2026 |
| Input modalities | text | text, image, video, file, audio |
| Arena · overall | #79 · ELO 1,436 | Unranked |
| Arena · Japanese | #67 · ELO 1,390 | Unranked |
| Arena · coding | #80 · ELO 1,484 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, DeepSeek V4 Flash: ¥32.17 per 1M output tokens, 95% less than Gemini 3.7 Flash.
- 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 Flash
The word "strawberry" is spelled as s-t-r-a-w-b-e-r-r-y. I go through each letter: s (no), t (no), r (yes, first), a (no), w (no), b (no), e (no), r (yes, second), r (yes, third), y (no). Thus, there are three 'r's.
3.9s251 output tokens
Gemini 3.7 Flash
There are **3** 'r's in the word "strawberry".
### Step-by-step reasoning:
1. **Break down the word into individual letters:**
* 1st letter: **s**
* 2nd letter: **t**
* 3rd letter: **r** *(1st 'r')*
* 4th letter: **a**
* 5th letter: **w**
* 6th letter: **b**
* 7th letter: **e**
* 8th letter: **r** *(2nd 'r')*
* 9th letter: **r** *(3rd 'r')*
* 10th letter: **y**
2. **Identify the positions of 'r':**
* The 3rd letter is an **r** (in "st**r**aw").
* The 8th letter is an **r** (in "be**r**ry").
* The 9th letter is an **r** (in "ber**r**y").
3. **Total count:** 1 + 1 + 1 = **3**.
4.5s530 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 Flash
The error occurs because `users` is `undefined` when the component tries to call `.map()` on it.
## Why this happens
Your component expects `users` to be an array, but it's receiving `undefined` as a prop. This typically happens when:
1. The parent component doesn't pass the `users` prop
2. The data fetching hasn't completed yet (async data loading)
3. The API response is missing the expected data structure
## How to fix it
### Option 1: Default prop value (Recommended for initial state)
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
### Option 2: Guard clause (More explicit)
```jsx
func…
6.3s422 output tokens
Gemini 3.7 Flash
### Why This Error Happens
This error occurs because the `users` prop is `undefined` when the component renders. Since `map` is an Array method, calling `undefined.map()` causes JavaScript to throw a `TypeError`.
This usually happens when:
1. Data is being fetched asynchronously (e.g., via `fetch` or `axios`), and the component renders **before** the data has arrived.
2. The parent component forgot to pass the `users` prop (`<UserList />`).
3. The initial state in the parent component was initialized as `undefined` (e.g., `const [users, setUsers] = useState()`).
---
### How to Fix It
Here are the best ways to fix it, depending on your use case:
#### Solution 1: Default Parameter (Recom…
9.9s1355 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 Flash
Here's a comprehensive review with suggested improvements:
## Issues Identified:
1. **Import at wrong location** - Imports inside functions are inefficient and non-standard
2. **Bare `except:` clause** - Catches all exceptions including `KeyboardInterrupt`, `SystemExit`
3. **Missing error handling granularity** - Should distinguish between retryable and non-retryable errors
4. **Duplicate sleep logic** - Same sleep in `else` and `except` blocks
5. **Unnecessary variable** - `data` is only used once
6. **Inefficient list building** - Manual loop instead of list comprehension
7. **Hardcoded error message** - No logging or error context
8. **Missing type hints** - No type annotations
9. **Fun…
12.6s987 output tokens
Gemini 3.7 Flash
Here is a detailed review of your function, followed by refactored versions.
---
### Key Issues & Areas for Improvement
1. **Imports inside the function (PEP 8):**
Imports should be placed at the top of the file, not inside a function, to avoid repeated import overhead and improve readability.
2. **Bare `except:` clause (Anti-pattern):**
Catching everything with `except:` intercepts `KeyboardInterrupt`, `SystemExit`, and memory errors, making debugging difficult. Catch specific exceptions like `requests.RequestException` and `ValueError` (for JSON decoding).
3. **Retrying on non-retryable errors:**
A status code like `404 Not Found` or `401 Unauthorized` will never succeed on a…
13.2s2117 output tokens
Frequently asked questions
- Which is cheaper, DeepSeek V4 Flash or Gemini 3.7 Flash?
- Per 1M output tokens, DeepSeek V4 Flash is ¥32.17 and Gemini 3.7 Flash is ¥670.13 on FastMetal (yen, before tax), so DeepSeek V4 Flash is cheaper.
- How do the context windows of DeepSeek V4 Flash and Gemini 3.7 Flash compare?
- DeepSeek V4 Flash takes 1,048,576 tokens; Gemini 3.7 Flash takes 1,048,576.
- Can I use DeepSeek V4 Flash and Gemini 3.7 Flash with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "deepseek-v4-flash" or "gemini-3.7-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 DeepSeek V4 Flash and Gemini 3.7 Flash from the browser chat and the API. No monthly fee.