Kimi K3.1 Pro vs MiMo-V2.6-Flash
Pricing, context window and real answers (October 2026)
Kimi K3.1 Pro (Moonshot) and MiMo-V2.6-Flash (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
 Kimi K3.1 Pro | MiMo-V2.6-Flash | |
|---|---|---|
| Provider | Moonshot | Xiaomi |
| Input (per 1M tokens) | $2.11 | $0.1477 |
| Output (per 1M tokens) | $10.55 | $0.2954 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | $7.39 | $0.2954 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Release date | 10/23/2026 | 9/21/2026 |
| Input modalities | text, image, video | text, image, video, audio |
| Throughput (p50) | — | 84 tokens/s (n=27) |
| Arena · overall | Unranked | #81 · ELO 1,448 |
| Arena · Japanese | Unranked | #132 · ELO 1,356 |
| Arena · coding | Unranked | #57 · ELO 1,511 |
Prices are FastMetal's rates, before tax.
Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-22; category names mapped and ratings rounded by FastMetal.
Which should you pick?
- On price, MiMo-V2.6-Flash: $0.2954 per 1M output tokens, 97% less than Kimi K3.1 Pro.
- 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.
Kimi K3.1 Pro
There are **3** ‘r’s in **“strawberry.”**
1. Write out each letter: **s – t – r – a – w – b – e – r – r – y**
2. Locate the ‘r’s: positions **3, 8, and 9**.
3. Count them: **1 + 1 + 1 = 3**.
11.3s
MiMo-V2.6-Flash
## Counting the 'r's in 'strawberry'
**Step 1: Write out each letter of the word individually:**
`s - t - r - a - w - b - e - r - r - y`
**Step 2: Go through each letter one by one and check if it's an 'r':**
| Position | Letter | Is it 'r'? | Running Count |
|----------|--------|------------|---------------|
| 1 | s | ❌ | 0 |
| 2 | t | ❌ | 0 |
| 3 | **r** | ✅ | **1** |
| 4 | a | ❌ | 1 |
| 5 | w | ❌ | 1 |
| 6 | b | ❌ | 1 |
| 7 | e | ❌ | 1 |
| 8 | **r** | ✅ | **2** |
| 9 | **r** | ✅ | **3** |
| 10 | y | ❌ | 3 |
**Answer: There are 3 'r's in 'strawberry'.** 🍓
The first 'r' appears at position 3 (after "st"), and the remaining two are the double 'rr' near the end of the word.
6.5s379 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…
Kimi K3.1 Pro
## What's causing the error
The error means `users` is `undefined` when the component renders, and you can't call `.map()` on `undefined`. The component itself is fine — the problem is that whatever renders `<UserList />` either isn't passing the prop, or is passing a value that isn't an array yet.
The most common cause is **async data fetching**: the parent renders `UserList` before the data has loaded.
```jsx
function App() {
const [users, setUsers] = useState(); // ❌ undefined on first render
useEffect(() => {
fetch('/api/users')
.then(res => res.json())
.then(setUsers);
}, []);
return <UserList users={users} />; // users is undefined here initially
}
```
On…
36.3s
MiMo-V2.6-Flash
## Cause of the Error
The error occurs because the `users` prop is `undefined` when the component first renders. When you try to call `.map()` on `undefined`, it throws:
```
TypeError: Cannot read properties of undefined (reading 'map')
```
This typically happens when:
1. The **parent component** hasn't passed `users` yet (e.g., data is still loading from an API)
2. The prop name **doesn't match** between parent and child
3. The prop is **intentionally optional** but used unconditionally
## Fixes
### 1. Default parameter value (simplest fix)
Set a default value for `users` so it's always an array:
```js
function UserList({ users = [] }) {
return (
<ul>
{users.map(user =>…
7.6s547 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):…
Kimi K3.1 Pro
The timeout and bounded retry loop are good starting points. The biggest issue is that failures—and even programming errors—are silently converted into retries and then `[]`.
### Suggested improvements
- **Avoid bare `except:`**. It catches `KeyboardInterrupt`, `KeyError`, JSON/schema errors, and other bugs. Retry only expected transient network failures; let malformed responses fail visibly.
- **Use a deliberate retry policy**. Retrying `401`, `403`, or `404` usually wastes time. Retry only transient statuses, use exponential backoff, and avoid sleeping after the final attempt.
- **Do not use `[]` for both failure and no results**. Prefer raising the final exception so callers can disting…
560.2s
MiMo-V2.6-Flash
# Code Review: `get_data`
## Issues Identified
| Category | Issue |
|----------|-------|
| **Readability** | Imports inside function, vague names (`i`, `r`), no docstring/type hints |
| **Performance** | Manual loop instead of list comprehension, no `requests.Session` (no connection reuse) |
| **Best Practices** | Bare `except`, `== True`, silent failures, no backoff, no error propagation |
---
## Improved Version
```python
import time
import logging
import requests
from typing import Optional
logger = logging.getLogger(__name__)
def get_data(
url: str,
retries: int = 3,
timeout: float = 10,
backoff_factor: float = 2.0,
) -> Optional[list[dict]]:
"""
Fetch dat…
18.9s1208 output tokens
Frequently asked questions
- Which is cheaper, Kimi K3.1 Pro or MiMo-V2.6-Flash?
- Per 1M output tokens, Kimi K3.1 Pro is $10.55 and MiMo-V2.6-Flash is $0.2954 on FastMetal (US dollars, before tax), so MiMo-V2.6-Flash is cheaper.
- How do the context windows of Kimi K3.1 Pro and MiMo-V2.6-Flash compare?
- Kimi K3.1 Pro takes 1,048,576 tokens; MiMo-V2.6-Flash takes 1,048,576.
- Can I use Kimi K3.1 Pro and MiMo-V2.6-Flash with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "kimi-k3.1-pro" or "mimo-v2.6-flash" 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 Kimi K3.1 Pro and MiMo-V2.6-Flash from the browser chat and the API. No monthly fee.