GPT-5.4 Nano vs Qwen3.8 2.4T A95B
Pricing, context window and real answers (September 2026)
GPT-5.4 Nano (OpenAI) 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
 GPT-5.4 Nano |  Qwen3.8 2.4T A95B | |
|---|---|---|
| Provider | OpenAI | Qwen |
| Input (per 1M tokens) | ¥35.74 | ¥351.83 |
| Output (per 1M tokens) | ¥223.38 | ¥1,055.5 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥147 | ¥880 |
| Context window | 400,000 tokens | 1,048,576 tokens |
| Release date | 3/17/2026 | 8/12/2026 |
| Input modalities | file, image, text | text |
| Throughput (p50) | — | — |
| Arena · overall | #146 · ELO 1,402 | Unranked |
| Arena · Japanese | #107 · ELO 1,368 | Unranked |
| Arena · coding | #128 · ELO 1,460 | Unranked |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, GPT-5.4 Nano: ¥223.38 per 1M output tokens, 79% less than Qwen3.8 2.4T A95B.
- For long documents, Qwen3.8 2.4T A95B: a 1,048,576-token context window against 400,000 for GPT-5.4 Nano.
- 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.
GPT-5.4 Nano
**Step 1:** Write the word: **strawberry**
**Step 2:** Count each letter **r** in the word:
- s **t r** a w b e **r r** y
There are **3** **r**’s in total (**one** after the **t**, and **two** near the end).
✅ **Answer: 3**
1.5s86 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…
GPT-5.4 Nano
This error means that **`users` is `undefined` (or otherwise not an array)** when your component renders, so calling `users.map(...)` throws:
```js
users.map(...)
^^^^ reading 'map' of undefined
```
### Why it happens
Common causes:
- You render `<UserList />` before data has loaded (e.g., `users` comes from an async fetch).
- The parent component passes the wrong prop name (e.g., `user` instead of `users`).
- The API/parent state initializes `users` as `undefined` rather than `[]`.
- You’re destructuring a prop incorrectly upstream.
### Fix options
#### 1) Ensure `users` is always an array (recommended)
Initialize/default it in the component:
```js
function UserList({ users = []…
3.3s383 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…
GPT-5.4 Nano
Subject: Project Update: Revised Delivery Timeline (Two-Week Delay)
Dear [Client Name],
I’m writing to share an important update regarding the delivery timeline for **[Project Name]**. First, please accept our sincere apologies for the inconvenience this may cause.
During **integration testing**, we discovered **unexpected technical challenges** that were not present earlier in our standalone development and verification activities. These issues require additional engineering work to ensure the solution performs reliably in the integrated environment and meets the agreed-upon requirements. As a result, we will need to adjust our delivery schedule.
## Revised Timeline
- **Original del…
3.7s519 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, GPT-5.4 Nano or Qwen3.8 2.4T A95B?
- Per 1M output tokens, GPT-5.4 Nano is ¥223.38 and Qwen3.8 2.4T A95B is ¥1,055.5 on FastMetal (yen, before tax), so GPT-5.4 Nano is cheaper.
- How do the context windows of GPT-5.4 Nano and Qwen3.8 2.4T A95B compare?
- GPT-5.4 Nano takes 400,000 tokens; Qwen3.8 2.4T A95B takes 1,048,576.
- Can I use GPT-5.4 Nano and Qwen3.8 2.4T A95B with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-5.4-nano" 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 GPT-5.4 Nano and Qwen3.8 2.4T A95B from the browser chat and the API. No monthly fee.