Claude Haiku 4.5 vs Qwen3.8 2.4T A95B
Pricing, context window and real answers (August 2026)
Claude Haiku 4.5 (Anthropic) and Qwen3.8 2.4T A95B (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
 Claude Haiku 4.5 |  Qwen3.8 2.4T A95B | |
|---|---|---|
| Provider | Anthropic | Qwen |
| Input (per 1M tokens) | ¥184.8 | ¥351.83 |
| Output (per 1M tokens) | ¥924 | ¥1,055.5 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥647 | ¥880 |
| Context window | 200,000 tokens | 1,048,576 tokens |
| Release date | 10/15/2025 | 8/12/2026 |
| Input modalities | image, text | text |
| Arena · overall | #129 · ELO 1,413 | Unranked |
| Arena · Japanese | #112 · ELO 1,357 | Unranked |
| Arena · coding | #95 · ELO 1,480 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, Claude Haiku 4.5: ¥924 per 1M output tokens, 12% less than Qwen3.8 2.4T A95B.
- For long documents, Qwen3.8 2.4T A95B: a 1,048,576-token context window against 200,000 for Claude Haiku 4.5.
- 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 Haiku 4.5
# Counting the 'r's in "strawberry"
Let me go through each letter in the word "strawberry":
1. **s** - not an 'r'
2. **t** - not an 'r'
3. **r** - this is an 'r' ✓ (1st)
4. **a** - not an 'r'
5. **w** - not an 'r'
6. **b** - not an 'r'
7. **e** - not an 'r'
8. **r** - this is an 'r' ✓ (2nd)
9. **r** - this is an 'r' ✓ (3rd)
10. **y** - not an 'r'
**Answer: There are 3 'r's in "strawberry"**
The 'r's appear in positions 3, 8, and 9 of the word.
4.1s228 output tokens
Qwen3.8 2.4T A95B
To count the number of **“r”**s in **“strawberry”**, spell it out letter by letter:
**s t r a w b e r r y**
Now check each letter:
1. s — not r
2. t — not r
3. r — yes, count 1
4. a — not r
5. w — not r
6. b — not r
7. e — not r
8. r — yes, count 2
9. r — yes, count 3
10. y — not r
So there are **3** “r”s in **strawberry**.
1.3s203 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 Haiku 4.5
# TypeError: Cannot read properties of undefined (reading 'map')
This error occurs because `users` is `undefined` when the component renders. You're trying to call `.map()` on `undefined`, which doesn't have that method.
## Common Causes
1. **Parent component didn't pass the `users` prop**
2. **Async data hasn't loaded yet**
3. **Props passed incorrectly**
## Solutions
### 1. **Provide a Default Value** (Recommended)
```javascript
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
### 2. **Add a Conditional Check**
```javascript
function UserList({ users }) {
if (!users) {
return <p>No users a…
3.9s671 output tokens
Qwen3.8 2.4T A95B
The error happens because `users` is `undefined` when React tries to render this line:
```js
{users.map(user => <li key={user.id}>{user.name}</li>)}
```
JavaScript cannot call `.map()` on `undefined`.
In your component:
```js
function UserList({ users }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</ul>
);
}
```
React expects `users` to be an array, but something is rendering `<UserList />` without providing a valid `users` prop.
---
## Common causes
### 1. The parent component is not passing `users`
For example:
```js
<UserList />
```
Instead of:
```js
<UserList users={users} />
```
---
### 2. The data has not loaded yet
If `users…
10.9s1318 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…
Claude Haiku 4.5
# Subject: Project Timeline Update – Revised Delivery Date and Mitigation Plan
Dear [Client Name],
I am writing to inform you of an important update regarding the [Project Name] delivery schedule.
**Timeline Adjustment**
During our integration testing phase, our team identified unexpected technical challenges that require additional resolution time. To ensure we deliver a product that meets our quality standards and your expectations, we have revised the delivery date to [new date], representing a two-week extension from our original timeline of [original date].
I sincerely apologize for this delay. We take full responsibility for the impact this may have on your planning, and I want to…
3.8s366 output tokens
Qwen3.8 2.4T A95B
Subject: Updated Project Timeline – Revised Delivery Date
Dear [Client Name],
I hope this message finds you well.
I’m writing to provide an important update regarding the delivery timeline for [Project Name]. During our recent integration testing phase, we identified several unexpected technical challenges that require additional resolution to ensure the final deliverable meets the quality and performance standards we committed to.
After carefully reviewing the scope of these items with our technical team, we have determined that the project delivery will need to be extended by two weeks. I sincerely apologize for any inconvenience this may cause. Please be assured that we are taking imm…
4.6s449 output tokens
Frequently asked questions
- Which is cheaper, Claude Haiku 4.5 or Qwen3.8 2.4T A95B?
- Per 1M output tokens, Claude Haiku 4.5 is ¥924 and Qwen3.8 2.4T A95B is ¥1,055.5 on FastMetal (yen, before tax), so Claude Haiku 4.5 is cheaper.
- How do the context windows of Claude Haiku 4.5 and Qwen3.8 2.4T A95B compare?
- Claude Haiku 4.5 takes 200,000 tokens; Qwen3.8 2.4T A95B takes 1,048,576.
- Can I use Claude Haiku 4.5 and Qwen3.8 2.4T A95B with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-haiku-4-5" or "qwen3.8-2.4t-a95b" 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 Haiku 4.5 and Qwen3.8 2.4T A95B from the browser chat and the API. No monthly fee.