Model comparison

GLM 5.1 vs Qwen3.8 27B

Pricing, context window and real answers (August 2026)

GLM 5.1 (Z.ai) and Qwen3.8 27B (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

z-ai logoGLM 5.1qwen logoQwen3.8 27B
ProviderZ.aiQwen
Input (per 1M tokens)¥250.18¥80.41
Output (per 1M tokens)¥786.28¥571.84
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥643¥366
Context window204,800 tokens1,000,000 tokens
Release date4/7/20268/14/2026
Input modalitiestexttext, image, video
Arena · overall#41 · ELO 1,466#87 · ELO 1,436
Arena · Japanese#49 · ELO 1,430Unranked
Arena · coding#36 · ELO 1,514#67 · ELO 1,498

Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.

Which should you pick?

  • On price, Qwen3.8 27B: ¥571.84 per 1M output tokens, 27% less than GLM 5.1.
  • On the Overall arena board, GLM 5.1 ranks higher (#41; Qwen3.8 27B is #87).
  • On the Coding arena board, GLM 5.1 ranks higher (#36; Qwen3.8 27B is #67).
  • For long documents, Qwen3.8 27B: 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 27B

The word is: **strawberry** Break it into letters: 1. s 2. t 3. r 4. a 5. w 6. b 7. e 8. r 9. r 10. y Now count the **r**’s: - 3rd letter: **r** - 8th letter: **r** - 9th letter: **r** So, there are **3** r’s in **strawberry**.
3.6s239 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 27B

The error means that `users` is `undefined` when `UserList` renders: ```jsx {users.map(...)} ``` JavaScript cannot call `.map()` on `undefined`. For example, this would cause the error: ```jsx <UserList /> ``` because `users` is not being passed in. ## Simple fix: give `users` a default value ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Now if `users` is not passed in, it defaults to an empty array. ## Better fix: make sure the parent passes an array Wherever you use `UserList`, pass `users`: ```jsx <UserList users={users} /> ``` If `users` comes from an API or state, make sure it…
9.5s601 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):…

GLM 5.1

Here is a review of your function, broken down by areas for improvement, followed by a refactored version of the code. ### Key Areas for Improvement 1. **Imports Inside the Function:** Placing `import` statements inside a function is generally discouraged in Python. It slows down the function execution every time it is called, and it violates PEP 8 (the Python style guide). Imports should always be at the top of the module. 2. **Bare `except` Clause:** Using a bare `except:` catches *everything*, including `KeyboardInterrupt` and `SystemExit`, which makes it hard to terminate a hanging program. You should catch specific exceptions (like `requests.exceptions.RequestException`). 3. *…
70.3s2854 output tokens

Qwen3.8 27B

The function works at a basic level, but it has several readability, reliability, and best-practice issues. ## Main issues 1. **Imports inside the function** ```python import requests import time ``` Imports should normally be at the top of the module unless there is a specific reason to lazy-load them. 2. **Bare `except` is too broad** ```python except: time.sleep(2) ``` This catches almost everything, including `KeyboardInterrupt`, `SystemExit`, `KeyError`, `TypeError`, and other programming errors. It makes debugging harder and can retry failures that should not be retried. 3. **It retries on every non-`200` status** Retrying `401 Unauthorized`, `4…
205.9s13103 output tokens

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Frequently asked questions

Which is cheaper, GLM 5.1 or Qwen3.8 27B?
Per 1M output tokens, GLM 5.1 is ¥786.28 and Qwen3.8 27B is ¥571.84 on FastMetal (yen, before tax), so Qwen3.8 27B is cheaper.
How do the context windows of GLM 5.1 and Qwen3.8 27B compare?
GLM 5.1 takes 204,800 tokens; Qwen3.8 27B takes 1,000,000.
Which ranks higher, GLM 5.1 or Qwen3.8 27B?
GLM 5.1 ranks higher on the public arena (GLM 5.1 #49, Qwen3.8 27B #87). Ranks move as the leaderboard updates.
Can I use GLM 5.1 and Qwen3.8 27B with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "glm-5.1" or "qwen3.8-27b" 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 27B from the browser chat and the API. No monthly fee.

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