MiMo-V2.5 vs MiMo-V2.5-Pro
Pricing, context window and real answers (August 2026)
MiMo-V2.5 (Xiaomi) and MiMo-V2.5-Pro (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
| MiMo-V2.5 | MiMo-V2.5-Pro | |
|---|---|---|
| Provider | Xiaomi | Xiaomi |
| Input (per 1M tokens) | ¥25.02 | ¥77.73 |
| Output (per 1M tokens) | ¥50.04 | ¥155.47 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥50 | ¥155 |
| Context window | 1,050,000 tokens | 1,050,000 tokens |
| Release date | 4/22/2026 | 4/22/2026 |
| Input modalities | text, audio, image, video | text |
| Arena · overall | #92 · ELO 1,434 | #40 · ELO 1,468 |
| Arena · Japanese | #137 · ELO 1,322 | #61 · ELO 1,418 |
| Arena · coding | #76 · ELO 1,491 | #27 · ELO 1,520 |
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, 68% less than MiMo-V2.5-Pro.
- On the Overall arena board, MiMo-V2.5-Pro ranks higher (#40; MiMo-V2.5 is #92).
- On the Japanese arena board, MiMo-V2.5-Pro ranks higher (#61; MiMo-V2.5 is #137).
- On the Coding arena board, MiMo-V2.5-Pro ranks higher (#27; MiMo-V2.5 is #76).
- 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.
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
MiMo-V2.5-Pro
## Counting the r's in "strawberry"
Let me go through each letter one by one:
| Position | Letter | Is it 'r'? |
|----------|--------|------------|
| 1 | s | No |
| 2 | t | No |
| 3 | **r** | ✅ Yes (#1) |
| 4 | a | No |
| 5 | w | No |
| 6 | b | No |
| 7 | e | No |
| 8 | **r** | ✅ Yes (#2) |
| 9 | **r** | ✅ Yes (#3) |
| 10 | y | No |
**There are 3 r's in "strawberry."**
The word breaks down as **straw·ber·ry**, and the r's appear at the end of "staw" and then twice in the double-r of "rry."
8.3s313 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…
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
MiMo-V2.5-Pro
# Fixing `Cannot read properties of undefined (reading 'map')`
## The Problem
The error means `users` is `undefined` when the component first renders. This typically happens when:
1. **The parent component hasn't passed the `users` prop**
2. **The data is being fetched asynchronously and isn't available yet**
3. **The prop name is misspelled in the parent**
For example, the parent might be rendering it like this:
```jsx
// ❌ No users prop passed — `users` will be undefined
<UserList />
```
## Solutions
### 1. Add a Default Prop Value (Simple Fix)
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}…
14.4s680 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):…
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
MiMo-V2.5-Pro
# Code Review: `get_data` Function
## Issues Identified
```
┌──────────────────────────────────────────────────────────────┐
│ ISSUE SEVERITY MAP │
├──────────────────┬────────────┬──────────────────────────────┤
│ Issue │ Severity │ Category │
├──────────────────┼────────────┼──────────────────────────────┤
│ Bare except │ 🔴 High │ Error Handling / Best Prac. │
│ Silent failures │ 🔴 High │ Debuggability │
│ == True check │ 🟡 Medium │ Readability / PEP 8 │
│ Inline imports │ 🟡 Medium │ Best Practice │
│ No type hints │ 🟡 Medium │ Best Practice…
10.4s1572 output tokens
Frequently asked questions
- Which is cheaper, MiMo-V2.5 or MiMo-V2.5-Pro?
- Per 1M output tokens, MiMo-V2.5 is ¥50.04 and MiMo-V2.5-Pro is ¥155.47 on FastMetal (yen, before tax), so MiMo-V2.5 is cheaper.
- How do the context windows of MiMo-V2.5 and MiMo-V2.5-Pro compare?
- MiMo-V2.5 takes 1,050,000 tokens; MiMo-V2.5-Pro takes 1,050,000.
- Which ranks higher, MiMo-V2.5 or MiMo-V2.5-Pro?
- MiMo-V2.5-Pro ranks higher on the public arena (MiMo-V2.5 #137, MiMo-V2.5-Pro #61). Ranks move as the leaderboard updates.
- Can I use MiMo-V2.5 and MiMo-V2.5-Pro with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "mimo-v2.5" or "mimo-v2.5-pro" 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 MiMo-V2.5 and MiMo-V2.5-Pro from the browser chat and the API. No monthly fee.