Model comparison

Grok 4.6 vs MiMo-V2.5

Pricing, context window and real answers (August 2026)

Grok 4.6 (xAI) 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

x-ai logoGrok 4.6MiMo-V2.5
ProviderxAIXiaomi
Input (per 1M tokens)¥357.4¥25.02
Output (per 1M tokens)¥1,072.2¥50.04
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥894¥50
Context window500,000 tokens1,050,000 tokens
Release date8/12/20264/22/2026
Input modalitiestext, image, filetext, audio, image, video
Arena · overall#48 · ELO 1,461#92 · ELO 1,434
Arena · JapaneseUnranked#137 · ELO 1,322
Arena · coding#44 · ELO 1,510#76 · 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, 95% less than Grok 4.6.
  • On the Overall arena board, Grok 4.6 ranks higher (#48; MiMo-V2.5 is #92).
  • On the Coding arena board, Grok 4.6 ranks higher (#44; MiMo-V2.5 is #76).
  • For long documents, MiMo-V2.5: a 1,050,000-token context window against 500,000 for Grok 4.6.
  • 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.

Grok 4.6

The word "strawberry" consists of the following letters in order: s-t-r-a-w-b-e-r-r-y Checking each one: - s: not r - t: not r - r: yes (count = 1) - a: not r - w: not r - b: not r - e: not r - r: yes (count = 2) - r: yes (count = 3) - y: not r There are exactly 3 r's. Final answer: 3
3.9s451 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…

Grok 4.6

**The error happens because `users` is `undefined` when `.map()` is called.** `UserList` destructures `{ users }` from its props. If the parent doesn't pass a `users` prop (or passes `undefined`/`null`), `users` is `undefined` and `undefined.map` throws. This is extremely common when: - Data is loaded asynchronously (initial render happens before the fetch finishes). - The parent component forgets to pass the prop or uses a different name. - The component is rendered before the data is ready (e.g. in a loading state). ### Quick fixes **1. Default to an empty array (recommended)** ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => ( <li key={us…
20.3s598 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):…

Grok 4.6

Here is a focused review of the function, followed by a cleaned-up version. ## Issues **Imports inside the function** `requests` and `time` should live at module level. Importing on every call is slower, hides dependencies, and is harder to mock in tests. **Bare `except:`** This swallows `KeyboardInterrupt`, `SystemExit`, and programming errors. Catch `requests.RequestException` (network/timeout/HTTP adapter errors) and JSON/`KeyError`/`TypeError` separately. **Retrying the wrong things** A 404 or 400 will never succeed on retry. Retry transient failures (timeouts, connection errors, 429, 5xx). Fail fast on most 4xx responses. **Sleep after the last attempt** On the final failur…
27.9s1770 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

Compare on more prompts →

Frequently asked questions

Which is cheaper, Grok 4.6 or MiMo-V2.5?
Per 1M output tokens, Grok 4.6 is ¥1,072.2 and MiMo-V2.5 is ¥50.04 on FastMetal (yen, before tax), so MiMo-V2.5 is cheaper.
How do the context windows of Grok 4.6 and MiMo-V2.5 compare?
Grok 4.6 takes 500,000 tokens; MiMo-V2.5 takes 1,050,000.
Which ranks higher, Grok 4.6 or MiMo-V2.5?
Grok 4.6 ranks higher on the public arena (Grok 4.6 #48, MiMo-V2.5 #137). Ranks move as the leaderboard updates.
Can I use Grok 4.6 and MiMo-V2.5 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "grok-4.6" 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 Grok 4.6 and MiMo-V2.5 from the browser chat and the API. No monthly fee.

More comparisons with Grok 4.6

More comparisons with MiMo-V2.5