Model comparison

GLM 5.2 vs Grok 4.5

Pricing, context window and real answers (August 2026)

GLM 5.2 (Z.ai) and Grok 4.5 (xAI), 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 5.2x-ai logoGrok 4.5
ProviderZ.aixAI
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 window1,048,576 tokens500,000 tokens
Release date6/16/20267/8/2026
Input modalitiestexttext, image, file
Arena · overall#31 · ELO 1,469#35 · ELO 1,468
Arena · Japanese#13 · ELO 1,472Unranked
Arena · coding#46 · ELO 1,506#28 · ELO 1,516

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, 27% less than Grok 4.5.
  • On the Overall arena board, GLM 5.2 ranks higher (#31; Grok 4.5 is #35).
  • On the Coding arena board, Grok 4.5 ranks higher (#28; GLM 5.2 is #46).
  • For long documents, GLM 5.2: a 1,048,576-token context window against 500,000 for Grok 4.5.
  • 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.

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

Grok 4.5

The word "strawberry" is spelled as follows: **s-t-r-a-w-b-e-r-r-y** - Position 1: **s** - Position 2: **t** - Position 3: **r** ← (1st "r") - Position 4: **a** - Position 5: **w** - Position 6: **b** - Position 7: **e** - Position 8: **r** ← (2nd "r") - Position 9: **r** ← (3rd "r") - Position 10: **y** There are **3** occurrences of the letter "r".
6.5s350 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 5.2

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

Grok 4.5

The error occurs because `users` is `undefined` when the component renders, so calling `.map()` on it fails. This commonly happens when: - The parent component doesn’t pass a `users` prop at all - The data is loaded asynchronously and is still `undefined` on the first render - The prop is accidentally set to `undefined`/`null` instead of an array ### Fixes **1. Default to an empty array (simplest)** ```js function UserList({ users = [] }) { return ( <ul> {users.map(user => ( <li key={user.id}>{user.name}</li> ))} </ul> ); } ``` **2. Optional chaining (also fine)** ```js function UserList({ users }) { return ( <ul> {users?.map(user => (…
7.9s507 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 5.2

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

Grok 4.5

## Code Review: `get_data` ### Issues | Area | Problem | |------|---------| | **Imports** | `requests` / `time` inside the function — re-imported on every call; belong at module level | | **Exceptions** | Bare `except:` swallows `KeyboardInterrupt`, `SystemExit`, and hides bugs | | **Boolean check** | `item["active"] == True` is unidiomatic; truthiness is enough | | **Loop** | Manual `for` + `append` can be a list comprehension | | **Retries** | Sleeps on non-200 but never logs or distinguishes failure modes; unused loop variable `i` | | **Robustness** | No guard for non-list JSON, missing keys (`KeyError`), or invalid JSON | | **API** | Magic numbers (`timeout=10`, `sleep=2`); no docstrin…
25.3s1363 output tokens

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Frequently asked questions

Which is cheaper, GLM 5.2 or Grok 4.5?
Per 1M output tokens, GLM 5.2 is ¥786.28 and Grok 4.5 is ¥1,072.2 on FastMetal (yen, before tax), so GLM 5.2 is cheaper.
How do the context windows of GLM 5.2 and Grok 4.5 compare?
GLM 5.2 takes 1,048,576 tokens; Grok 4.5 takes 500,000.
Which ranks higher, GLM 5.2 or Grok 4.5?
GLM 5.2 ranks higher on the public arena (GLM 5.2 #13, Grok 4.5 #35). Ranks move as the leaderboard updates.
Can I use GLM 5.2 and Grok 4.5 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "glm-5.2" or "grok-4.5" 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 5.2 and Grok 4.5 from the browser chat and the API. No monthly fee.

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