Gemini 3.1 Pro Preview vs GLM 5.3 Flash
Pricing, context window and real answers (September 2026)
Gemini 3.1 Pro Preview (Google) and GLM 5.3 Flash (Z.ai), 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
 Gemini 3.1 Pro Preview |  GLM 5.3 Flash | |
|---|---|---|
| Provider | Z.ai | |
| Input (per 1M tokens) | ¥357.4 | ¥26.81 |
| Output (per 1M tokens) | ¥2,144.4 | ¥89.35 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥1,430 | ¥71 |
| Context window | 1,048,576 tokens | 1,310,720 tokens |
| Release date | 2/19/2026 | 8/26/2026 |
| Input modalities | audio, file, image, text, video | text, image, video |
| Throughput (p50) | — | — |
| Arena · overall | #15 · ELO 1,487 | #29 · ELO 1,475 |
| Arena · Japanese | #9 · ELO 1,494 | #51 · ELO 1,427 |
| Arena · coding | #28 · ELO 1,520 | #20 · ELO 1,525 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, GLM 5.3 Flash: ¥89.35 per 1M output tokens, 96% less than Gemini 3.1 Pro Preview.
- On the Overall arena board, Gemini 3.1 Pro Preview ranks higher (#15; GLM 5.3 Flash is #29).
- On the Japanese arena board, Gemini 3.1 Pro Preview ranks higher (#9; GLM 5.3 Flash is #51).
- On the Coding arena board, GLM 5.3 Flash ranks higher (#20; Gemini 3.1 Pro Preview is #28).
- For long documents, GLM 5.3 Flash: a 1,310,720-token context window against 1,048,576 for Gemini 3.1 Pro Preview.
- 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.
Gemini 3.1 Pro Preview
There are **3** 'r's in the word 'strawberry'.
Here is the step-by-step breakdown of the spelling:
1. **s** - not an 'r'
2. **t** - not an 'r'
3. **r** - **1st 'r'**
4. **a** - not an 'r'
5. **w** - not an 'r'
6. **b** - not an 'r'
7. **e** - not an 'r'
8. **r** - **2nd 'r'**
9. **r** - **3rd 'r'**
10. **y** - not an 'r'
Therefore, the total count is 3.
5.3s503 output tokens
GLM 5.3 Flash
# Counting 'r's in 'strawberry'
**Step 1: Write out the word letter by letter**
s - t - r - a - w - b - e - r - r - y
**Step 2: Check each letter one at a time**
| Position | Letter | Is it 'r'? |
|----------|--------|-----------|
| 1 | s | No |
| 2 | t | No |
| 3 | r | **Yes! (1)** |
| 4 | a | No |
| 5 | w | No |
| 6 | b | No |
| 7 | e | No |
| 8 | r | **Yes! (2)** |
| 9 | r | **Yes! (3)** |
| 10 | y | No |
**Step 3: Add up the matches**
The 'r's appear at positions 3, 8, and 9.
## Answer: There are **3** 'r's in "strawberry" 🍓
7.2s449 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…
Gemini 3.1 Pro Preview
### The Cause
This error occurs because the `users` prop being passed to your `UserList` component is currently `undefined`.
In JavaScript, you can only use the `.map()` method on arrays. Because `users` is `undefined` (often due to data not finishing an API fetch yet, or the parent component forgetting to pass the prop), Node/React throws an error when it tries to read `.map`.
### How to Fix It
You can fix this in a few different ways, depending on how you want your application to behave.
#### Fix 1: Assign a Default Value (Recommended)
The cleanest way to handle this is to assign a default empty array to `users` in your component's parameters. If `users` is undefined, it defaults to…
13.2s1511 output tokens
GLM 5.3 Flash
## What's happening
The error means the `users` prop is `undefined` at the time `UserList` renders. Since you can't call `.map()` on `undefined`, JavaScript throws the TypeError.
This usually happens for one of these reasons:
1. **The parent isn't passing the prop** — rendering `<UserList />` without `users`, or with a typo'd prop name like `user={users}`.
2. **Data hasn't loaded yet** — the parent fetches data asynchronously and its state starts as `undefined`:
```jsx
const [users, setUsers] = useState(); // undefined until fetch resolves!
return <UserList users={users} />;
```
3. **API response shape mismatch** — the array is nested, e.g., you need `response.data.users` inst…
31.3s1639 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):…
Gemini 3.1 Pro Preview
Here is a review of your function. While the original code works, there are several areas where it can be improved regarding **best practices**, **readability**, and **performance**.
### 1. Refactored Code
Here is the improved version of your function. I will explain the specific changes below.
```python
import time
import requests
import logging
from typing import Any
# Optional: Set up a logger
logger = logging.getLogger(__name__)
def get_data(url: str, retries: int = 3, delay: int = 2, timeout: int = 10) -> list[dict[str, Any]]:
"""
Fetches JSON data from a URL and extracts active items.
Args:
url: The API endpoint to fetch data from.
retries: Number o…
23.6s3094 output tokens
GLM 5.3 Flash
Solid foundation — you're already passing an explicit `timeout` and implementing retries, which many people skip. Here's a breakdown by category:
## Correctness & robustness (most important)
- **Bare `except:`** catches *everything*, including `KeyboardInterrupt` and `SystemExit`, and silently discards the error. Catch specific exceptions: `requests.RequestException` for network issues, `ValueError` for invalid JSON.
- **Retrying non-retryable failures**: a 401/403/404 will never succeed on retry, so you're sleeping 6 seconds for nothing. Only retry transient errors (5xx, 429, timeouts/connection errors).
- **`item["active"]` raises `KeyError`** on malformed data. Use `item.get("active")`…
116.1s6185 output tokens
Frequently asked questions
- Which is cheaper, Gemini 3.1 Pro Preview or GLM 5.3 Flash?
- Per 1M output tokens, Gemini 3.1 Pro Preview is ¥2,144.4 and GLM 5.3 Flash is ¥89.35 on FastMetal (yen, before tax), so GLM 5.3 Flash is cheaper.
- How do the context windows of Gemini 3.1 Pro Preview and GLM 5.3 Flash compare?
- Gemini 3.1 Pro Preview takes 1,048,576 tokens; GLM 5.3 Flash takes 1,310,720.
- Which ranks higher, Gemini 3.1 Pro Preview or GLM 5.3 Flash?
- Gemini 3.1 Pro Preview ranks higher on the public arena (Gemini 3.1 Pro Preview #9, GLM 5.3 Flash #51). Ranks move as the leaderboard updates.
- Can I use Gemini 3.1 Pro Preview and GLM 5.3 Flash with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.1-pro-preview" or "glm-5.3-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 Gemini 3.1 Pro Preview and GLM 5.3 Flash from the browser chat and the API. No monthly fee.