Grok 4.5 vs Qwen3.8 2.4T A95B
Pricing, context window and real answers (August 2026)
Grok 4.5 (xAI) 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
 Grok 4.5 |  Qwen3.8 2.4T A95B | |
|---|---|---|
| Provider | xAI | Qwen |
| Input (per 1M tokens) | ¥357.4 | ¥351.83 |
| Output (per 1M tokens) | ¥1,072.2 | ¥1,055.5 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥894 | ¥880 |
| Context window | 500,000 tokens | 1,048,576 tokens |
| Release date | 7/8/2026 | 8/12/2026 |
| Input modalities | text, image, file | text |
| Arena · overall | #36 · ELO 1,470 | Unranked |
| Arena · Japanese | #39 · ELO 1,441 | Unranked |
| Arena · coding | #21 · ELO 1,523 | 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 2.4T A95B: ¥1,055.5 per 1M output tokens, 2% less than Grok 4.5.
- For long documents, Qwen3.8 2.4T A95B: a 1,048,576-token context window against 500,000 for Grok 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.
Grok 4.5
The word "strawberry" is spelled as follows:
**s-t-r-a-w-b-e-r-r-y**
- Position 1: **s**
- Position 2: **t**
- Position 3: **r** ← (1st "r")
- Position 4: **a**
- Position 5: **w**
- Position 6: **b**
- Position 7: **e**
- Position 8: **r** ← (2nd "r")
- Position 9: **r** ← (3rd "r")
- Position 10: **y**
There are **3** occurrences of the letter "r".
6.5s350 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…
Grok 4.5
The error occurs because `users` is `undefined` when the component renders, so calling `.map()` on it fails.
This commonly happens when:
- The parent component doesn’t pass a `users` prop at all
- The data is loaded asynchronously and is still `undefined` on the first render
- The prop is accidentally set to `undefined`/`null` instead of an array
### Fixes
**1. Default to an empty array (simplest)**
```js
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
```
**2. Optional chaining (also fine)**
```js
function UserList({ users }) {
return (
<ul>
{users?.map(user => (…
7.9s507 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…
Grok 4.5
Subject: Update on Project Timeline – Revised Delivery Date
Dear [Client Name],
I am writing to provide you with an important update regarding the [Project Name] delivery schedule.
During integration testing, our team encountered unexpected technical challenges that require additional time to resolve properly. As a result, we need to adjust the project delivery date by two weeks. I sincerely apologize for any inconvenience this may cause and for not meeting the original timeline we committed to.
We remain fully confident in our ability to deliver a high-quality solution. To address the issues efficiently and minimize further impact, we have already implemented the following mitigation st…
9.0s391 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, Grok 4.5 or Qwen3.8 2.4T A95B?
- Per 1M output tokens, Grok 4.5 is ¥1,072.2 and Qwen3.8 2.4T A95B is ¥1,055.5 on FastMetal (yen, before tax), so Qwen3.8 2.4T A95B is cheaper.
- How do the context windows of Grok 4.5 and Qwen3.8 2.4T A95B compare?
- Grok 4.5 takes 500,000 tokens; Qwen3.8 2.4T A95B takes 1,048,576.
- Can I use Grok 4.5 and Qwen3.8 2.4T A95B with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "grok-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 Grok 4.5 and Qwen3.8 2.4T A95B from the browser chat and the API. No monthly fee.