Model comparison

GPT-6 Sol vs Inkling

Pricing, context window and real answers (September 2026)

GPT-6 Sol (OpenAI) and Inkling (Thinking Machines), 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 SolInkling
ProviderOpenAIThinking Machines
Input (per 1M tokens)¥357.4¥178.7
Output (per 1M tokens)¥1,787¥723.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥1,251¥541
Context window1,050,000 tokens524,288 tokens
Release date9/22/20267/17/2026
Input modalitiesfile, image, texttext, image, audio
Throughput (p50)
Arena · overallUnranked#85 · ELO 1,440
Arena · JapaneseUnranked#63 · ELO 1,415
Arena · codingUnranked#78 · ELO 1,492

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

Which should you pick?

  • On price, Inkling: ¥723.74 per 1M output tokens, 59% less than GPT-6 Sol.
  • For long documents, GPT-6 Sol: a 1,050,000-token context window against 524,288 for Inkling.
  • 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

Inkling

Let's break down the word **"strawberry"** letter by letter: 1. **s** 2. **t** 3. **r** ← (1st 'r') 4. **a** 5. **w** 6. **b** 7. **e** 8. **r** ← (2nd 'r') 9. **r** ← (3rd 'r') 10. **y** So the spelling is: s-t-**r**-a-w-b-e-**r**-**r**-y Counting them up: - One 'r' in "str" (the 3rd letter) - Two 'r's in "berry" (the 8th and 9th letters) **Total: 3 'r's** in "strawberry".**
2.4s417 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

Inkling

The error occurs because `users` is `undefined` when `UserList` renders, so `users.map` fails. This usually happens when: - The parent doesn't pass the prop (`<UserList />` instead of `<UserList users={...} />`) - Data is still loading (e.g., API hasn't returned yet) ## Quick Fix Provide a default empty array so `.map` always has an array to work with: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Alternatively, guard against undefined explicitly: ```jsx function UserList({ users }) { if (!users) return null; // or a loading state return ( <ul> {users.map(user => <li key={…
4.9s585 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

Inkling

Here is a review with an improved version followed by explanations. ### Issues in the original - **Imports inside the function**: Re-importing on every call is inefficient. - **Bare `except:`**: Catches `SystemExit`, `KeyboardInterrupt`, etc. - **Silent failures**: No logging; errors disappear. - **Magic numbers**: `10`, `2`, `200` are hard-coded. - **Data validation missing**: Assumes `data` is a list and every item has `"active"`, `"name"`, and `"id"` (will crash with `KeyError`). - **Performance**: Uses `.append()` in a loop instead of a list comprehension. - **Ambiguous return**: `[]` means both "success with no results" and "total failure". ### Improved version ```python import loggi…
54.1s5649 output tokens

Compare on more prompts →

Frequently asked questions

Which is cheaper, GPT-6 Sol or Inkling?
Per 1M output tokens, GPT-6 Sol is ¥1,787 and Inkling is ¥723.74 on FastMetal (yen, before tax), so Inkling is cheaper.
How do the context windows of GPT-6 Sol and Inkling compare?
GPT-6 Sol takes 1,050,000 tokens; Inkling takes 524,288.
Can I use GPT-6 Sol and Inkling with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-sol" or "inkling" 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 Inkling from the browser chat and the API. No monthly fee.

More comparisons with GPT-6 Sol

More comparisons with Inkling