GLM 5.1 vs Qwen3.8 Max
Pricing, context window and real answers (August 2026)
GLM 5.1 (Z.ai) and Qwen3.8 Max (Qwen), 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
 GLM 5.1 |  Qwen3.8 Max | |
|---|---|---|
| Provider | Z.ai | Qwen |
| Input (per 1M tokens) | ¥250.18 | ¥357.4 |
| Output (per 1M tokens) | ¥786.28 | ¥1,072.2 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥643 | ¥894 |
| Context window | 204,800 tokens | 1,000,000 tokens |
| Release date | 4/7/2026 | 8/3/2026 |
| Input modalities | text | text, image |
| Arena · overall | #41 · ELO 1,466 | #20 · ELO 1,479 |
| Arena · Japanese | #49 · ELO 1,430 | #14 · ELO 1,485 |
| Arena · coding | #36 · ELO 1,514 | #26 · ELO 1,520 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, GLM 5.1: ¥786.28 per 1M output tokens, 27% less than Qwen3.8 Max.
- On the Overall arena board, Qwen3.8 Max ranks higher (#20; GLM 5.1 is #41).
- On the Japanese arena board, Qwen3.8 Max ranks higher (#14; GLM 5.1 is #49).
- On the Coding arena board, Qwen3.8 Max ranks higher (#26; GLM 5.1 is #36).
- For long documents, Qwen3.8 Max: a 1,000,000-token context window against 204,800 for GLM 5.1.
- 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.
GLM 5.1
There are **3** 'r's in the word "strawberry".
Here is the step-by-step reasoning:
1. Let's break down the word "strawberry" letter by letter: s - t - r - a - w - b - e - r - r - y
2. Now, let's check each letter one by one to see if it is an 'r':
- **s**: not an 'r'
- **t**: not an 'r'
- **r**: this is the 1st 'r'
- **a**: not an 'r'
- **w**: not an 'r'
- **b**: not an 'r'
- **e**: not an 'r'
- **r**: this is the 2nd 'r'
- **r**: this is the 3rd 'r'
- **y**: not an 'r'
3. Counting them up, there are three 'r's in total (in the 3rd, 8th, and 9th positions).
7.3s565 output tokens
Qwen3.8 Max
The word **strawberry** is spelled:
**s t r a w b e r r y**
Now count the letter **r**:
1. s
2. t
3. **r** ← first r
4. a
5. w
6. b
7. e
8. **r** ← second r
9. **r** ← third r
10. y
There are **3** letters **r** in **strawberry**.
3.5s156 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…
GLM 5.1
### What is causing the error?
The error `TypeError: Cannot read properties of undefined (reading 'map')` means you are trying to call the `.map()` method on a variable that is `undefined`.
In your code, the variable is `users`. When the `UserList` component renders, the `users` prop is `undefined`, so `undefined.map()` throws an error.
### Why is `users` undefined?
This usually happens for one of two reasons:
1. **You forgot to pass the prop:** The parent component rendering `<UserList />` is not passing the `users` attribute (e.g., `<UserList />` instead of `<UserList users={myUsers} />`).
2. **Async Data Fetching:** You are fetching the users from an API. On the initial render, befor…
45.0s1680 output tokens
Qwen3.8 Max
The error means `users` is `undefined` when `UserList` tries to render:
```js
{users.map(user => ...)}
```
JavaScript cannot call `.map()` on `undefined`, so React throws:
```text
Cannot read properties of undefined (reading 'map')
```
## Most likely cause
The parent component is rendering `UserList` without passing a valid `users` array, or it is passing `users` before the data has loaded.
For example:
```jsx
<UserList />
```
or:
```jsx
<UserList users={undefined} />
```
or:
```jsx
const [users, setUsers] = useState(); // undefined initially
```
Then later:
```jsx
<UserList users={users} />
```
On the first render, `users` is still `undefined`.
---
## Fix 1: Give `users` a d…
17.7s1020 output tokens
Professional Email
Write a professional email to a client explaining that the project delivery will be delayed by two weeks due to unexpected technical challenges discovered during integration testing. The tone should be apologetic but con…
GLM 5.1
Subject: Project Update: Revised Timeline for [Project Name]
Dear [Client Name],
I am writing to provide a transparent update regarding the progress of [Project Name].
During our recent integration testing phase, our team uncovered unexpected technical challenges that require additional time to resolve correctly. While we had anticipated standard integration adjustments, the specific complexities we encountered demand a more thorough approach to ensure the system's stability and performance.
As a result, we must adjust our final delivery date by two weeks. Our new projected delivery date is [New Delivery Date].
I sincerely apologize for any inconvenience this delay may cause to your…
22.5s1618 output tokens
Qwen3.8 Max
Subject: Revised Project Delivery Timeline – Updated Schedule and Next Steps
Dear [Client Name],
I hope this message finds you well.
I am writing to provide an update on the current status of the project and to inform you that, during our recent integration testing phase, we encountered several unexpected technical challenges that will impact the original delivery timeline. After careful review with the technical team, we now anticipate the revised delivery date will be [insert date – two weeks from original delivery date].
Please accept my sincere apologies for this delay. We understand the importance of this project and the expectations tied to the original schedule. While this situati…
11.9s547 output tokens
Frequently asked questions
- Which is cheaper, GLM 5.1 or Qwen3.8 Max?
- Per 1M output tokens, GLM 5.1 is ¥786.28 and Qwen3.8 Max is ¥1,072.2 on FastMetal (yen, before tax), so GLM 5.1 is cheaper.
- How do the context windows of GLM 5.1 and Qwen3.8 Max compare?
- GLM 5.1 takes 204,800 tokens; Qwen3.8 Max takes 1,000,000.
- Which ranks higher, GLM 5.1 or Qwen3.8 Max?
- Qwen3.8 Max ranks higher on the public arena (GLM 5.1 #49, Qwen3.8 Max #14). Ranks move as the leaderboard updates.
- Can I use GLM 5.1 and Qwen3.8 Max with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "glm-5.1" or "qwen3.8-max" 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 GLM 5.1 and Qwen3.8 Max from the browser chat and the API. No monthly fee.