Model comparison

GPT-6 Sol vs MiMo-V2.5

Pricing, context window and real answers (September 2026)

GPT-6 Sol (OpenAI) and MiMo-V2.5 (Xiaomi), 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 SolMiMo-V2.5
ProviderOpenAIXiaomi
Input (per 1M tokens)¥357.4¥25.02
Output (per 1M tokens)¥1,787¥50.04
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥1,251¥50
Context window1,050,000 tokens1,050,000 tokens
Release date9/22/20264/22/2026
Input modalitiesfile, image, texttext, audio, image, video
Throughput (p50)
Arena · overallUnranked#96 · ELO 1,434
Arena · JapaneseUnranked#141 · ELO 1,321
Arena · codingUnranked#81 · ELO 1,491

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

Which should you pick?

  • On price, MiMo-V2.5: ¥50.04 per 1M output tokens, 97% less than GPT-6 Sol.
  • 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

MiMo-V2.5

# Counting the 'r's in 'strawberry' Let me spell the word out letter by letter: | Position | Letter | Is it 'r'? | |----------|--------|------------| | 1 | **s** | ❌ | | 2 | **t** | ❌ | | 3 | **r** | ✅ (1) | | 4 | **a** | ❌ | | 5 | **w** | ❌ | | 6 | **b** | ❌ | | 7 | **e** | ❌ | | 8 | **r** | ✅ (2) | | 9 | **r** | ✅ (3) | | 10 | **y** | ❌ | ## Answer: **3** 'r's The three r's are found at positions **3**, **8**, and **9** in the word.
14.9s313 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

MiMo-V2.5

This error occurs because your `users` prop is `undefined` when the component tries to call `.map()` on it. This usually happens when: 1. The parent component doesn't pass a `users` prop 2. The `users` data is still loading (asynchronous operation) 3. There's a typo in the prop name when passing from parent ## How to Fix It ### 1. Add Default Props or Prop Validation Add a default value for the `users` prop: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } // Or with PropTypes import PropTypes from 'prop-types'; function UserList({ users }) { return ( <ul> {users.map(user => <li key…
11.2s808 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

MiMo-V2.5

# Code Review: `get_data` Function ## Issues Identified | Category | Issue | Severity | |----------|-------|----------| | Style | Imports inside function body | Medium | | Reliability | Bare `except` catches `KeyboardInterrupt`/`SystemExit` | High | | Reliability | Silent failures — no logging | Medium | | Readability | `== True` comparison (redundant) | Low | | Readability | No docstring or type hints | Medium | | Performance | Could use list comprehension | Low | | Robustness | No exponential backoff on retries | Medium | | Robustness | `r.json()` can fail silently under bare except | High | | Style | Uninformative variable names (`r`, `i`) | Low | | Config | Magic numbers hardcoded (`ti…
33.6s1854 output tokens

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Frequently asked questions

Which is cheaper, GPT-6 Sol or MiMo-V2.5?
Per 1M output tokens, GPT-6 Sol is ¥1,787 and MiMo-V2.5 is ¥50.04 on FastMetal (yen, before tax), so MiMo-V2.5 is cheaper.
How do the context windows of GPT-6 Sol and MiMo-V2.5 compare?
GPT-6 Sol takes 1,050,000 tokens; MiMo-V2.5 takes 1,050,000.
Can I use GPT-6 Sol and MiMo-V2.5 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-sol" or "mimo-v2.5" 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 MiMo-V2.5 from the browser chat and the API. No monthly fee.

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