Claude Fable 5 vs MiMo-V2.6-Pro
Pricing, context window and real answers (September 2026)
Claude Fable 5 (Anthropic) and MiMo-V2.6-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
 Claude Fable 5 | MiMo-V2.6-Pro | |
|---|---|---|
| Provider | Anthropic | Xiaomi |
| Input (per 1M tokens) | ¥1,787 | ¥77.73 |
| Output (per 1M tokens) | ¥8,935 | ¥155.47 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥6,255 | ¥155 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Release date | 6/9/2026 | 9/21/2026 |
| Input modalities | text, image, file | text, image, video, audio |
| Throughput (p50) | — | — |
| Arena · overall | #1 · ELO 1,506 | Unranked |
| Arena · Japanese | #1 · ELO 1,523 | Unranked |
| Arena · coding | #1 · ELO 1,552 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, MiMo-V2.6-Pro: ¥155.47 per 1M output tokens, 98% less than Claude Fable 5.
- For long documents, MiMo-V2.6-Pro: a 1,048,576-token context window against 1,000,000 for Claude Fable 5.
- 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.
Claude Fable 5
# Counting 'r's in "strawberry"
Let me spell out the word letter by letter and check each one:
| Position | Letter | Is it 'r'? |
|----------|--------|------------|
| 1 | s | No |
| 2 | t | No |
| 3 | **r** | ✅ Yes (1st) |
| 4 | a | No |
| 5 | w | No |
| 6 | b | No |
| 7 | e | No |
| 8 | **r** | ✅ Yes (2nd) |
| 9 | **r** | ✅ Yes (3rd) |
| 10 | y | No |
## Reasoning breakdown:
- The word "strawberry" can be split into two parts: **straw** + **berry**
- "straw" contains one 'r': st**r**aw
- "berry" contains two 'r's: be**rr**y (a double-r)
## Answer: **3**
There are **three 'r's** in "strawberry."
39.6s354 output tokens
MiMo-V2.6-Pro
# Counting the 'r's in "strawberry"
## Step 1: Spell out the word letter by letter
| Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|----------|---|---|---|---|---|---|---|---|---|----|
| Letter | s | t | r | a | w | b | e | r | r | y |
## Step 2: Identify every 'r'
- **Position 3** → **r** ✅ (1st 'r')
- **Position 8** → **r** ✅ (2nd 'r')
- **Position 9** → **r** ✅ (3rd 'r')
All other letters (s, t, a, w, b, e, y) are not 'r'.
## Answer
There are **3** 'r's in "strawberry."
22.0s327 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…
Claude Fable 5
## Cause
The error means that when `UserList` renders, the `users` prop is `undefined`, so calling `.map()` on it fails. This typically happens for one of these reasons:
1. **The parent isn't passing the prop** (or has a typo in the prop name):
```jsx
<UserList /> // users is undefined
<UserList user={users} /> // typo: "user" instead of "users"
```
2. **Data is fetched asynchronously** — the component renders before the API call finishes, and the initial state is `undefined`:
```jsx
const [users, setUsers] = useState(); // undefined initially!
```
## Fixes
**Option 1: Default parameter value** (quick fix)
```jsx
function UserList({ users = [] }) {
re…
51.3s686 output tokens
MiMo-V2.6-Pro
# Fixing `Cannot read properties of undefined (reading 'map')`
## The Problem
The `users` prop is `undefined` when the component renders. This happens because `.map()` is being called on something that doesn't exist — JavaScript can't iterate over `undefined`.
This typically occurs when:
- The parent component doesn't pass the `users` prop at all
- The data is still loading (e.g., from an API call)
- A destructuring default doesn't exist
## The Fix
### Option 1: Provide a default value (simplest)
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
### Option 2: Add a safety check with conditi…
32.9s575 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):…
Claude Fable 5
# Code Review
Your function works, but there are several issues worth addressing. Here's a breakdown by category:
## Issues Found
### 1. **Bare `except:` clause (critical)**
This catches *everything*, including `KeyboardInterrupt`, `SystemExit`, and bugs like `KeyError` or `TypeError` in your own parsing code. You'll silently retry on programming errors and mask real problems.
### 2. **Imports inside the function**
Imports belong at module level (PEP 8). Function-level imports add overhead on each call and hide dependencies.
### 3. **`== True` comparison**
Use truthiness directly: `if item["active"]:` (PEP 8 explicitly recommends this).
### 4. **Silent failures**
Returning `[]` on fail…
38.5s1528 output tokens
MiMo-V2.6-Pro
# Code Review: `get_data` Function
## Issues Identified
Here's my review organized by category, with a final improved version at the end.
---
### 🔴 Best Practices
1. **Imports inside the function** — `import requests` and `import time` are executed on *every* call. Move them to the top of the file (module-level).
2. **Bare `except:`** — This catches *everything*, including `KeyboardInterrupt` and `SystemExit`. Always catch specific exceptions.
3. **`== True` comparison** — Verbose and unnecessary. Use the object's truthiness directly.
4. **No logging** — Silent failures make debugging nearly impossible.
5. **Magic numbers** — `timeout=10` and `time.sleep(2)` are unexplained constan…
42.5s983 output tokens
Frequently asked questions
- Which is cheaper, Claude Fable 5 or MiMo-V2.6-Pro?
- Per 1M output tokens, Claude Fable 5 is ¥8,935 and MiMo-V2.6-Pro is ¥155.47 on FastMetal (yen, before tax), so MiMo-V2.6-Pro is cheaper.
- How do the context windows of Claude Fable 5 and MiMo-V2.6-Pro compare?
- Claude Fable 5 takes 1,000,000 tokens; MiMo-V2.6-Pro takes 1,048,576.
- Can I use Claude Fable 5 and MiMo-V2.6-Pro with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-fable-5" or "mimo-v2.6-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 Claude Fable 5 and MiMo-V2.6-Pro from the browser chat and the API. No monthly fee.