Model comparison

GLM 5.2 vs GPT-5 Mini

Pricing, context window and real answers (September 2026)

GLM 5.2 (Z.ai) and GPT-5 Mini (OpenAI), 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 5.2openai logoGPT-5 Mini
ProviderZ.aiOpenAI
Input (per 1M tokens)¥235.2¥44.68
Output (per 1M tokens)¥739.2¥357.4
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥605¥223
Context window1,048,576 tokens400,000 tokens
Release date6/16/20268/7/2025
Input modalitiestexttext, image, file
Throughput (p50)
Arena · overall#38 · ELO 1,472#163 · ELO 1,390
Arena · Japanese#28 · ELO 1,452#109 · ELO 1,365
Arena · coding#48 · ELO 1,510#172 · ELO 1,431

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

Which should you pick?

  • On price, GPT-5 Mini: ¥357.4 per 1M output tokens, 52% less than GLM 5.2.
  • On the Overall arena board, GLM 5.2 ranks higher (#38; GPT-5 Mini is #163).
  • On the Japanese arena board, GLM 5.2 ranks higher (#28; GPT-5 Mini is #109).
  • On the Coding arena board, GLM 5.2 ranks higher (#48; GPT-5 Mini is #172).
  • For long documents, GLM 5.2: a 1,048,576-token context window against 400,000 for GPT-5 Mini.
  • 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

GPT-5 Mini

We examine the word "strawberry" letter by letter: 1. s — not an r (count = 0) 2. t — not an r (count = 0) 3. r — an r (count = 1) 4. a — not an r (count = 1) 5. w — not an r (count = 1) 6. b — not an r (count = 1) 7. e — not an r (count = 1) 8. r — an r (count = 2) 9. r — an r (count = 3) 10. y — not an r (count = 3) Total number of 'r's = 3.
5.2s382 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

GPT-5 Mini

That error means users is undefined when you call users.map(...). map is an Array method, so calling it on undefined throws "Cannot read properties of undefined (reading 'map')". Common causes - The parent component didn't pass a users prop. - users is still loading (e.g. fetched asynchronously) and is null/undefined until the fetch completes. - The parent initialized users to null instead of an empty array. How to fix Choose one or more of these approaches depending on your app: 1) Initialize the parent state as an array If users is state in the parent, initialize it to [] so the child always receives an array: const [users, setUsers] = useState([]); // fetch and setUsers(data) 2) Give…
8.0s966 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

GPT-5 Mini

Thanks — this is a nice simple function, but it can be improved in several ways: move imports to module scope, avoid broad except:, use connection pooling (Session) for performance, use specific exception types, add logging and docstring, avoid comparing to True, use list comprehensions, validate JSON shape, and implement backoff (or use urllib3 Retry). Below are two improved alternatives and a short rationale for the changes. 1) A simple, clear improvement (small changes, explicit errors, backoff + jitter) - Moves imports to top-level - Uses requests.Session for connection pooling - Catches specific exceptions (requests.RequestException, ValueError) - Uses list comprehension and item.get(…
13.6s1702 output tokens

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Frequently asked questions

Which is cheaper, GLM 5.2 or GPT-5 Mini?
Per 1M output tokens, GLM 5.2 is ¥739.2 and GPT-5 Mini is ¥357.4 on FastMetal (yen, before tax), so GPT-5 Mini is cheaper.
How do the context windows of GLM 5.2 and GPT-5 Mini compare?
GLM 5.2 takes 1,048,576 tokens; GPT-5 Mini takes 400,000.
Which ranks higher, GLM 5.2 or GPT-5 Mini?
GLM 5.2 ranks higher on the public arena (GLM 5.2 #28, GPT-5 Mini #109). Ranks move as the leaderboard updates.
Can I use GLM 5.2 and GPT-5 Mini with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "glm-5.2" or "gpt-5-mini" 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 GPT-5 Mini from the browser chat and the API. No monthly fee.

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