Model comparison

GLM 5.2 vs Pareto

Pricing, context window and real answers (September 2026)

GLM 5.2 (Z.ai) and Pareto (Unbiased), 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 5.2Pareto
ProviderZ.aiUnbiased
Input (per 1M tokens)¥235.2¥446.75
Output (per 1M tokens)¥739.2¥1,340.25
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥605¥1,117
Context window1,048,576 tokens262,144 tokens
Release date6/16/20269/17/2026
Input modalitiestexttext, image
Throughput (p50)
Arena · overall#38 · ELO 1,472Unranked
Arena · Japanese#28 · ELO 1,452Unranked
Arena · coding#48 · ELO 1,510Unranked

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: ¥739.2 per 1M output tokens, 45% less than Pareto.
  • For long documents, GLM 5.2: a 1,048,576-token context window against 262,144 for Pareto.
  • 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

Pareto

To count the number of 'r's in the word "strawberry," let's break it down letter by letter: 1. **s** - not an 'r' 2. **t** - not an 'r' 3. **r** - **Yes**, this is the first 'r'. 4. **a** - not an 'r' 5. **w** - not an 'r' 6. **b** - not an 'r' 7. **e** - not an 'r' 8. **r** - **Yes**, this is the second 'r'. 9. **r** - **Yes**, this is the third 'r'. 10. **y** - not an 'r' Counting the occurrences: - The 3rd letter is 'r'. - The 8th letter is 'r'. - The 9th letter is 'r'. There are **3** 'r's in "strawberry".
5.5s225 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

Pareto

The error means `users` is `undefined` when `UserList` renders. Destructuring a prop does **not** protect against it: ```jsx function UserList({ users }) { // users can still be undefined return <ul>{users.map(...)}</ul>; // 💥 } ``` This usually happens when: - The parent renders `<UserList />` without passing `users` - The parent’s state starts as `undefined` before an async fetch finishes - The API response is not an array, or `users` is passed as `undefined` ## Fix 1: Default the prop to an empty array ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => ( <li key={user.id}>{user.name}</li> ))} </ul> ); } ``` This works when…
11.6s1478 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

Pareto

The function is straightforward, but its error handling hides failures and retries requests that may never succeed. ### Main improvements - **Move imports to module scope** for readability and conventional dependency management. - **Avoid bare `except:`.** It catches everything, including programming errors and `KeyboardInterrupt`. Catch specific request failures instead. - **Retry selectively.** Timeouts, connection failures, rate limits, and certain server errors may be temporary; most other HTTP errors should surface immediately. - **Use exponential backoff** and avoid sleeping after the last attempt. - **Use a list comprehension** to express the filtering and transformation directly. -…
30.3s1090 output tokens

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Frequently asked questions

Which is cheaper, GLM 5.2 or Pareto?
Per 1M output tokens, GLM 5.2 is ¥739.2 and Pareto is ¥1,340.25 on FastMetal (yen, before tax), so GLM 5.2 is cheaper.
How do the context windows of GLM 5.2 and Pareto compare?
GLM 5.2 takes 1,048,576 tokens; Pareto takes 262,144.
Can I use GLM 5.2 and Pareto with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "glm-5.2" or "pareto" 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 Pareto from the browser chat and the API. No monthly fee.

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