Model comparison

GPT-5.6 Terra vs Qwen3.8 27B

Pricing, context window and real answers (August 2026)

GPT-5.6 Terra (OpenAI) 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

openai logoGPT-5.6 Terraqwen logoQwen3.8 27B
ProviderOpenAIQwen
Input (per 1M tokens)¥357.4¥80.41
Output (per 1M tokens)¥2,144.4¥571.84
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥1,430¥366
Context window1,050,000 tokens1,000,000 tokens
Release date7/9/20268/14/2026
Input modalitiesfile, image, texttext, image, video
Arena · overall#42 · ELO 1,466#87 · ELO 1,436
Arena · Japanese#19 · ELO 1,474Unranked
Arena · coding#31 · ELO 1,519#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, 73% less than GPT-5.6 Terra.
  • On the Overall arena board, GPT-5.6 Terra ranks higher (#42; Qwen3.8 27B is #87).
  • On the Coding arena board, GPT-5.6 Terra ranks higher (#31; Qwen3.8 27B is #67).
  • For long documents, GPT-5.6 Terra: a 1,050,000-token context window against 1,000,000 for Qwen3.8 27B.
  • 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.

GPT-5.6 Terra

“strawberry” is spelled: s t **r** a w b e **r** **r** y There are **3** occurrences of the letter **r**.
3.6s71 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…

GPT-5.6 Terra

The error means `users` is `undefined` when `UserList` renders, so React tries to evaluate: ```js users.map(...) ``` But `.map()` only exists on arrays. Common causes: - The parent component does not pass a `users` prop. - The user data is loaded asynchronously and has not arrived on the first render. - The API response shape differs from what you expect, e.g. data is in `response.data.users` rather than `response.data`. - The parent initializes its user state as `undefined` or `null`. ## Fix options ### 1. Initialize users as an empty array In the parent component: ```jsx const [users, setUsers] = useState([]); ``` Then pass it normally: ```jsx <UserList users={users} /> ``` An e…
5.8s559 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):…

GPT-5.6 Terra

Here are the main areas to improve: ### Issues in the original code - **Imports inside the function**: Move `requests` and `time` imports to module scope. - **Bare `except:`**: This catches everything, including `KeyboardInterrupt` and programming errors. Catch `requests.RequestException` (and possibly JSON decoding errors) instead. - **Status code check**: Prefer `response.raise_for_status()` or `response.ok` over manually checking only for `200`. Successful responses can include other 2xx status codes. - **`== True`**: Use `if item.get("active"):` instead. - **Potential `KeyError`**: `item["name"]`, `item["id"]`, and `item["active"]` can fail if the API response is incomplete. Use `.get(…
10.6s939 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, GPT-5.6 Terra or Qwen3.8 27B?
Per 1M output tokens, GPT-5.6 Terra is ¥2,144.4 and Qwen3.8 27B is ¥571.84 on FastMetal (yen, before tax), so Qwen3.8 27B is cheaper.
How do the context windows of GPT-5.6 Terra and Qwen3.8 27B compare?
GPT-5.6 Terra takes 1,050,000 tokens; Qwen3.8 27B takes 1,000,000.
Which ranks higher, GPT-5.6 Terra or Qwen3.8 27B?
GPT-5.6 Terra ranks higher on the public arena (GPT-5.6 Terra #19, Qwen3.8 27B #87). Ranks move as the leaderboard updates.
Can I use GPT-5.6 Terra and Qwen3.8 27B with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-5.6-terra" 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 GPT-5.6 Terra and Qwen3.8 27B from the browser chat and the API. No monthly fee.

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