Model comparison

GPT-6 Sol vs Muse Spark 1.2

Pricing, context window and real answers (September 2026)

GPT-6 Sol (OpenAI) and Muse Spark 1.2 (Meta), 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-6 Solmeta logoMuse Spark 1.2
ProviderOpenAIMeta
Input (per 1M tokens)¥357.4¥219.9
Output (per 1M tokens)¥1,787¥747.65
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥1,251¥594
Context window1,050,000 tokens1,048,576 tokens
Release date9/22/20268/5/2026
Input modalitiesfile, image, texttext, image, video, file, audio
Throughput (p50)
Arena · overallUnranked#4 · ELO 1,500
Arena · JapaneseUnrankedUnranked
Arena · codingUnranked#9 · ELO 1,536

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

Which should you pick?

  • On price, Muse Spark 1.2: ¥747.65 per 1M output tokens, 58% less than GPT-6 Sol.
  • For long documents, GPT-6 Sol: a 1,050,000-token context window against 1,048,576 for Muse Spark 1.2.
  • 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-6 Sol

“Strawberry” is spelled **s-t-r-a-w-b-e-r-r-y**. There’s one **r** near the beginning and two near the end, for a total of **3**.
2.7s76 output tokens

Muse Spark 1.2

There are **3** 'r's in "strawberry". Here is my reasoning step by step: 1. Write out the word and its spelling: **s-t-r-a-w-b-e-r-r-y** 2. Go through each letter one by one and check if it is an 'r': * 1. s - not an 'r' -> count = 0 * 2. t - not an 'r' -> count = 0 * 3. **r** - yes, it's 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** - yes, it's an 'r' -> count = 2 * 9. **r** - yes, it's an 'r' -> count = 3 * 10. y - not an 'r' -> count = 3 3. Final total = **3**.
13.3s1123 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-6 Sol

`users` is `undefined` when `UserList` renders, so calling `users.map(...)` throws the error. The component needs an array, but its parent may not be passing `users`, or the data may not have loaded yet. You can default it to an empty array: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Also check the parent component to make sure it passes an array: ```jsx <UserList users={users} /> ``` If `users` comes from an API, initialize its state as `[]` or show a loading state until the data arrives.
2.2s161 output tokens

Muse Spark 1.2

This error means `users` is `undefined` when the component tries to render. You are calling `.map()` on `users` at line 12, but `.map()` only exists on arrays. If `users` is `undefined` or `null`, JavaScript throws: `Cannot read properties of undefined (reading 'map')`. This usually happens for 2 reasons: 1. You didn't pass the `users` prop to the component: `<UserList />` 2. Your data is async and `users` is `undefined` on the first render. For example: `const [users, setUsers] = useState()` without an initial value, and the data hasn't been fetched yet. ### Fix it You need to guarantee `users` is always an array before you call `.map()`. #### 1. Best Fix: Give it a default value U…
7.6s1142 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-6 Sol

The main issues are the bare `except`, which hides errors such as malformed JSON, and retrying every non-200 response, including client errors that usually won’t improve with another attempt. The function also sleeps after its final attempt. ```python import time import requests def get_data(url, retries=3): if retries < 1: raise ValueError("retries must be at least 1") for attempt in range(retries): try: response = requests.get(url, timeout=10) except requests.RequestException: if attempt == retries - 1: raise else: # Retry rate limits and server errors, but not other client errors.…
10.3s814 output tokens

Muse Spark 1.2

Here is a review of your function with a refactored, production-ready version: ### Issues in the Current Version #### 1. Readability 1. **Generic name:** `get_data` tells nothing about what it does. `get_active_items` is better. 2. **Imports inside function:** `import requests, time` should be at the top of the file. It's slower and violates PEP 8. 3. **Magic numbers:** `200`, `10`, `2` have no context. 4. **Verbose loop:** Manual `for` loop + `append` can be replaced with a list comprehension. 5. **No documentation/typing:** No docstring, no type hints, so callers don't know what it expects or returns. 6. **`== True` is redundant:** `if item["active"] == True:` should be `if item["a…
11.8s2278 output tokens

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Frequently asked questions

Which is cheaper, GPT-6 Sol or Muse Spark 1.2?
Per 1M output tokens, GPT-6 Sol is ¥1,787 and Muse Spark 1.2 is ¥747.65 on FastMetal (yen, before tax), so Muse Spark 1.2 is cheaper.
How do the context windows of GPT-6 Sol and Muse Spark 1.2 compare?
GPT-6 Sol takes 1,050,000 tokens; Muse Spark 1.2 takes 1,048,576.
Can I use GPT-6 Sol and Muse Spark 1.2 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-sol" or "muse-spark-1.2" 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-6 Sol and Muse Spark 1.2 from the browser chat and the API. No monthly fee.

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