Kimi K3 vs Qwen3.8 Max
Pricing, context window and real answers (August 2026)
Kimi K3 (Moonshot) and Qwen3.8 Max (Qwen), 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 |  Qwen3.8 Max | |
|---|---|---|
| Provider | Moonshot | Qwen |
| Input (per 1M tokens) | ¥536.1 | ¥357.4 |
| Output (per 1M tokens) | ¥2,680.5 | ¥1,072.2 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥1,876 | ¥894 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Release date | 7/16/2026 | 8/3/2026 |
| Input modalities | text, image | text, image |
| Arena · overall | #11 · ELO 1,486 | Unranked |
| Arena · Japanese | Unranked | Unranked |
| Arena · coding | #8 · ELO 1,530 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Qwen3.8 Max: ¥1,072.2 per 1M output tokens, 60% less than Kimi K3.
- For long documents, Kimi K3: a 1,048,576-token context window against 1,000,000 for Qwen3.8 Max.
- 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
# Counting the 'r's in "strawberry"
**Step 1: Write out each letter with its position**
| Position | Letter |
|----------|--------|
| 1 | s |
| 2 | t |
| 3 | **r** ✓ |
| 4 | a |
| 5 | w |
| 6 | b |
| 7 | e |
| 8 | **r** ✓ |
| 9 | **r** ✓ |
| 10 | y |
**Step 2: Identify each 'r'**
- Position 3: the 'r' in "st**r**"
- Position 8: the first 'r' in "be**r**ry"
- Position 9: the second 'r' in "ber**r**y"
**Step 3: Verify by splitting the word**
"Strawberry" = "straw" + "berry"
- "straw" contains **1** r
- "berry" contains **2** r's
**Answer: There are 3 r's in "strawberry."** 🍓
12.2s594 output tokens
Qwen3.8 Max
The word **strawberry** is spelled:
**s t r a w b e r r y**
Now count the letter **r**:
1. s
2. t
3. **r** ← first r
4. a
5. w
6. b
7. e
8. **r** ← second r
9. **r** ← third r
10. y
There are **3** letters **r** in **strawberry**.
3.5s156 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
## What's causing it
The error means `users` is `undefined` when the component renders — `.map()` only exists on arrays, so calling it on `undefined` throws. Your component code is fine; the problem is **upstream**: whatever renders `<UserList />` isn't passing a valid array.
The most common culprit is **async data fetching with uninitialized state** in the parent:
```jsx
function App() {
const [users, setUsers] = useState(); // ← undefined!
useEffect(() => {
fetch('/api/users')
.then(res => res.json())
.then(setUsers);
}, []);
return <UserList users={users} />; // undefined on first render
}
```
The component renders *before* the fetch resolves, so `users` is `…
47.5s1756 output tokens
Qwen3.8 Max
The error means `users` is `undefined` when `UserList` tries to render:
```js
{users.map(user => ...)}
```
JavaScript cannot call `.map()` on `undefined`, so React throws:
```text
Cannot read properties of undefined (reading 'map')
```
## Most likely cause
The parent component is rendering `UserList` without passing a valid `users` array, or it is passing `users` before the data has loaded.
For example:
```jsx
<UserList />
```
or:
```jsx
<UserList users={undefined} />
```
or:
```jsx
const [users, setUsers] = useState(); // undefined initially
```
Then later:
```jsx
<UserList users={users} />
```
On the first render, `users` is still `undefined`.
---
## Fix 1: Give `users` a d…
17.7s1020 output tokens
Professional Email
Write a professional email to a client explaining that the project delivery will be delayed by two weeks due to unexpected technical challenges discovered during integration testing. The tone should be apologetic but con…
Kimi K3
**Subject:** Important Update: [Project Name] Delivery Timeline
Dear [Client Name],
I'm writing to inform you of an important update regarding the [Project Name] delivery schedule. During integration testing this week, our team uncovered unexpected technical challenges that require additional development work. As a result, we need to adjust our delivery date from [Original Date] to [New Date] — a two-week extension.
To be transparent about what happened: the integration between [System A] and [System B] revealed compatibility issues that weren't apparent during earlier development phases. While any delay is disappointing, I'm encouraged that our testing process caught these issues now rat…
104.7s1605 output tokens
Qwen3.8 Max
Subject: Revised Project Delivery Timeline – Updated Schedule and Next Steps
Dear [Client Name],
I hope this message finds you well.
I am writing to provide an update on the current status of the project and to inform you that, during our recent integration testing phase, we encountered several unexpected technical challenges that will impact the original delivery timeline. After careful review with the technical team, we now anticipate the revised delivery date will be [insert date – two weeks from original delivery date].
Please accept my sincere apologies for this delay. We understand the importance of this project and the expectations tied to the original schedule. While this situati…
11.9s547 output tokens
Frequently asked questions
- Which is cheaper, Kimi K3 or Qwen3.8 Max?
- Per 1M output tokens, Kimi K3 is ¥2,680.5 and Qwen3.8 Max is ¥1,072.2 on FastMetal (yen, before tax), so Qwen3.8 Max is cheaper.
- How do the context windows of Kimi K3 and Qwen3.8 Max compare?
- Kimi K3 takes 1,048,576 tokens; Qwen3.8 Max takes 1,000,000.
- Can I use Kimi K3 and Qwen3.8 Max with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "kimi-k3" or "qwen3.8-max" 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 and Qwen3.8 Max from the browser chat and the API. No monthly fee.