Claude Fable 5 vs GLM 5.2
Pricing, context window and real answers (August 2026)
Claude Fable 5 (Anthropic) and GLM 5.2 (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
 Claude Fable 5 |  GLM 5.2 | |
|---|---|---|
| Provider | Anthropic | Z.ai |
| Input (per 1M tokens) | ¥1,787 | ¥250.18 |
| Output (per 1M tokens) | ¥8,935 | ¥786.28 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥6,255 | ¥643 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Release date | 6/9/2026 | 6/16/2026 |
| Input modalities | text, image, file | text |
| Arena · overall | #1 · ELO 1,508 | #31 · ELO 1,469 |
| Arena · Japanese | #1 · ELO 1,529 | #13 · ELO 1,472 |
| Arena · coding | #2 · ELO 1,552 | #46 · ELO 1,506 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, GLM 5.2: ¥786.28 per 1M output tokens, 91% less than Claude Fable 5.
- On the Overall arena board, Claude Fable 5 ranks higher (#1; GLM 5.2 is #31).
- On the Japanese arena board, Claude Fable 5 ranks higher (#1; GLM 5.2 is #13).
- On the Coding arena board, Claude Fable 5 ranks higher (#2; GLM 5.2 is #46).
- For long documents, GLM 5.2: a 1,048,576-token context window against 1,000,000 for Claude Fable 5.
- 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.
Claude Fable 5
# Counting 'r's in "strawberry"
Let me spell out the word letter by letter and check each one:
| Position | Letter | Is it 'r'? |
|----------|--------|------------|
| 1 | s | No |
| 2 | t | No |
| 3 | **r** | ✅ Yes (1st) |
| 4 | a | No |
| 5 | w | No |
| 6 | b | No |
| 7 | e | No |
| 8 | **r** | ✅ Yes (2nd) |
| 9 | **r** | ✅ Yes (3rd) |
| 10 | y | No |
## Reasoning breakdown:
- The word "strawberry" can be split into two parts: **straw** + **berry**
- "straw" contains one 'r': st**r**aw
- "berry" contains two 'r's: be**rr**y (a double-r)
## Answer: **3**
There are **three 'r's** in "strawberry."
39.6s354 output tokens
GLM 5.2
To count the number of 'r's in the word 'strawberry', let's look at the word letter by letter:
1. **s** - no 'r'
2. **t** - no 'r'
3. **r** - this is the 1st 'r'
4. **a** - no 'r'
5. **w** - no 'r'
6. **b** - no 'r'
7. **e** - no 'r'
8. **r** - this is the 2nd 'r'
9. **r** - this is the 3rd 'r'
10. **y** - no 'r'
Total count: 3
There are **3** 'r's in the word 'strawberry'.
2.6s439 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…
Claude Fable 5
## Cause
The error means that when `UserList` renders, the `users` prop is `undefined`, so calling `.map()` on it fails. This typically happens for one of these reasons:
1. **The parent isn't passing the prop** (or has a typo in the prop name):
```jsx
<UserList /> // users is undefined
<UserList user={users} /> // typo: "user" instead of "users"
```
2. **Data is fetched asynchronously** — the component renders before the API call finishes, and the initial state is `undefined`:
```jsx
const [users, setUsers] = useState(); // undefined initially!
```
## Fixes
**Option 1: Default parameter value** (quick fix)
```jsx
function UserList({ users = [] }) {
re…
51.3s686 output tokens
GLM 5.2
The error `TypeError: Cannot read properties of undefined (reading 'map')` happens because the `users` prop being passed to your `UserList` component is currently `undefined`. When JavaScript tries to call `.map()` on `undefined`, it throws this error.
Here are the best ways to fix this:
### Fix 1: Provide a default value (Recommended)
You can provide a default empty array `[]` when destructuring the props. This ensures that even if `users` is not passed down, the `.map()` function will still have an array to iterate over (resulting in an empty list rather than a crash).
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</…
8.3s1006 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):…
Claude Fable 5
# Code Review
Your function works, but there are several issues worth addressing. Here's a breakdown by category:
## Issues Found
### 1. **Bare `except:` clause (critical)**
This catches *everything*, including `KeyboardInterrupt`, `SystemExit`, and bugs like `KeyError` or `TypeError` in your own parsing code. You'll silently retry on programming errors and mask real problems.
### 2. **Imports inside the function**
Imports belong at module level (PEP 8). Function-level imports add overhead on each call and hide dependencies.
### 3. **`== True` comparison**
Use truthiness directly: `if item["active"]:` (PEP 8 explicitly recommends this).
### 4. **Silent failures**
Returning `[]` on fail…
38.5s1528 output tokens
GLM 5.2
Here is a review of your Python function, broken down by readability, performance, and best practices, followed by a refactored version of the code.
### 1. Best Practices
* **Move imports to the top:** Importing modules inside a function is generally discouraged. While Python caches imports, putting `import requests` and `import time` at the top of your file is the standard convention and improves readability.
* **Avoid bare `except:` blocks:** Using a bare `except:` catches everything, including `KeyboardInterrupt` and `SystemExit`. This makes it hard to interrupt your program if it gets stuck in a loop. You should catch specific exceptions, such as `requests.exceptions.RequestException` (…
10.9s2061 output tokens
Frequently asked questions
- Which is cheaper, Claude Fable 5 or GLM 5.2?
- Per 1M output tokens, Claude Fable 5 is ¥8,935 and GLM 5.2 is ¥786.28 on FastMetal (yen, before tax), so GLM 5.2 is cheaper.
- How do the context windows of Claude Fable 5 and GLM 5.2 compare?
- Claude Fable 5 takes 1,000,000 tokens; GLM 5.2 takes 1,048,576.
- Which ranks higher, Claude Fable 5 or GLM 5.2?
- Claude Fable 5 ranks higher on the public arena (Claude Fable 5 #1, GLM 5.2 #13). Ranks move as the leaderboard updates.
- Can I use Claude Fable 5 and GLM 5.2 with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-fable-5" or "glm-5.2" 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 Claude Fable 5 and GLM 5.2 from the browser chat and the API. No monthly fee.