Model comparison

Claude Sonnet 4.6 vs Qwen3.8 27B

Pricing, context window and real answers (August 2026)

Claude Sonnet 4.6 (Anthropic) 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

anthropic logoClaude Sonnet 4.6qwen logoQwen3.8 27B
ProviderAnthropicQwen
Input (per 1M tokens)¥554.4¥80.41
Output (per 1M tokens)¥2,772¥571.84
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥1,940¥366
Context window1,000,000 tokens1,000,000 tokens
Release date2/17/20268/14/2026
Input modalitiestext, imagetext, image, video
Arena · overall#32 · ELO 1,472#87 · ELO 1,436
Arena · Japanese#41 · ELO 1,438Unranked
Arena · coding#14 · ELO 1,528#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, 79% less than Claude Sonnet 4.6.
  • On the Overall arena board, Claude Sonnet 4.6 ranks higher (#32; Qwen3.8 27B is #87).
  • On the Coding arena board, Claude Sonnet 4.6 ranks higher (#14; Qwen3.8 27B is #67).
  • 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 Sonnet 4.6

## Counting the letter 'r' in 'strawberry' Let me go through the word letter by letter: | Position | Letter | Is it 'r'? | |----------|--------|------------| | 1 | s | No | | 2 | t | No | | 3 | r | ✅ Yes | | 4 | a | No | | 5 | w | No | | 6 | b | No | | 7 | e | No | | 8 | r | ✅ Yes | | 9 | r | ✅ Yes | | 10 | y | No | ## Result There are **3 r's** in 'strawberry'.
2.2s181 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…

Claude Sonnet 4.6

## Problem Analysis The error occurs because `users` is `undefined` when the component renders. You're calling `.map()` on `undefined`, which throws a `TypeError`. **Common causes:** - The prop isn't passed by the parent component - Data is still loading asynchronously when the component first renders - The parent passes `undefined` or a misspelled prop name --- ## Solutions ### Option 1: Default Parameter Value (Simplest Fix) ```javascript function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` This assigns an empty array if `users` is `undefined`, so `.map()` always has an array to work with. --- ###…
9.4s798 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):…

Claude Sonnet 4.6

## Code Review and Improvements ### Issues Identified 1. **Imports inside function** – should be at module level 2. **Bare `except`** – catches everything including `KeyboardInterrupt`, `SystemExit` 3. **`== True` comparison** – not Pythonic 4. **No logging/error visibility** – silent failures make debugging hard 5. **Magic numbers** – hardcoded `2`, `10` with no explanation 6. **No distinction between retriable/non-retriable errors** – e.g., 404 should not be retried 7. **Inefficient list building** – list comprehension is cleaner 8. **No exponential backoff** – fixed sleep is naive for real-world retry logic 9. **Missing type hints and docstring** --- ### Improved Version ```python im…
14.4s1099 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, Claude Sonnet 4.6 or Qwen3.8 27B?
Per 1M output tokens, Claude Sonnet 4.6 is ¥2,772 and Qwen3.8 27B is ¥571.84 on FastMetal (yen, before tax), so Qwen3.8 27B is cheaper.
How do the context windows of Claude Sonnet 4.6 and Qwen3.8 27B compare?
Claude Sonnet 4.6 takes 1,000,000 tokens; Qwen3.8 27B takes 1,000,000.
Which ranks higher, Claude Sonnet 4.6 or Qwen3.8 27B?
Claude Sonnet 4.6 ranks higher on the public arena (Claude Sonnet 4.6 #41, Qwen3.8 27B #87). Ranks move as the leaderboard updates.
Can I use Claude Sonnet 4.6 and Qwen3.8 27B with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-sonnet-4-6" 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 Claude Sonnet 4.6 and Qwen3.8 27B from the browser chat and the API. No monthly fee.

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