gpt-oss-20b vs Qwen3.8 Max
Pricing, context window and real answers (September 2026)
gpt-oss-20b (OpenAI) 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
 gpt-oss-20b |  Qwen3.8 Max | |
|---|---|---|
| Provider | OpenAI | Qwen |
| Input (per 1M tokens) | ¥5.36 | ¥357.4 |
| Output (per 1M tokens) | ¥25.02 | ¥1,072.2 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥18 | ¥894 |
| Context window | 131,072 tokens | 1,000,000 tokens |
| Release date | 8/5/2025 | 8/3/2026 |
| Input modalities | text | text, image |
| Throughput (p50) | — | — |
| Arena · overall | #252 · ELO 1,317 | #22 · ELO 1,481 |
| Arena · Japanese | #179 · ELO 1,256 | #18 · ELO 1,469 |
| Arena · coding | #232 · ELO 1,369 | #24 · ELO 1,522 |
Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.
Which should you pick?
- On price, gpt-oss-20b: ¥25.02 per 1M output tokens, 98% less than Qwen3.8 Max.
- On the Overall arena board, Qwen3.8 Max ranks higher (#22; gpt-oss-20b is #252).
- On the Japanese arena board, Qwen3.8 Max ranks higher (#18; gpt-oss-20b is #179).
- On the Coding arena board, Qwen3.8 Max ranks higher (#24; gpt-oss-20b is #232).
- For long documents, Qwen3.8 Max: a 1,000,000-token context window against 131,072 for gpt-oss-20b.
- 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-oss-20b
**Count of ‘r’ in “strawberry”: 3**
---
### Step‑by‑step reasoning
1. **Write out the word in individual letters**
```
s t r a w b e r r y
```
2. **Identify each ‘r’**
- The first ‘r’: appears after the “t” → **r**
- The second ‘r’: appears in the part “berry” → **r**
- The third ‘r’: the next letter after that → **r**
3. **Verify there are no more letters left**
The remaining letters are “b”, “e”, “y”, none of which are “r”.
4. **Count the identified ‘r’s**
1 (first) + 1 (second) + 1 (third) = **3**
---
### Quick recap
- Word: **strawberry**
- Letters containing “r”: positions 3, 8, and 9.
- Total count: **3**.
11.6s371 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…
gpt-oss-20b
### Why does the error happen?
`users.map(...)` can only run when **`users` is an array**.
The stack trace shows that the crash happens on line 12 of `UserList.js`, which is the
exact spot where the code tries to call `.map`.
The value that is being passed to `UserList` (or the initial value that the parent
creates) is **`undefined`** (or it could be `null`/`{}`). When JavaScript tries to
read `users.map`, it throws:
```
TypeError: Cannot read properties of undefined (reading 'map')
```
Typical reasons for this are:
1. The parent component **didn’t pass the `users` prop** at all.
2. The parent passed it but the value was **`undefined` / `null`** because data
hasn’t been loaded ye…
11.4s1303 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…
gpt-oss-20b
**Subject:** Updated Delivery Timeline for [Project Name] – Immediate Action Plan
Dear [Client Name],
I hope you are doing well.
I am writing to inform you of an important development that will affect the delivery schedule of the [Project Name] project. During our integration testing phase we discovered a series of unforeseen technical challenges that require additional work to resolve before the system can be released in a stable, production‑ready state.
**Why the delay?**
The issues involve [briefly describe “critical data consistency checks” or “third‑party API integration glitches”] that were not evident during earlier phases. These bugs have a direct impact on the core functionali…
6.9s860 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, gpt-oss-20b or Qwen3.8 Max?
- Per 1M output tokens, gpt-oss-20b is ¥25.02 and Qwen3.8 Max is ¥1,072.2 on FastMetal (yen, before tax), so gpt-oss-20b is cheaper.
- How do the context windows of gpt-oss-20b and Qwen3.8 Max compare?
- gpt-oss-20b takes 131,072 tokens; Qwen3.8 Max takes 1,000,000.
- Which ranks higher, gpt-oss-20b or Qwen3.8 Max?
- Qwen3.8 Max ranks higher on the public arena (gpt-oss-20b #179, Qwen3.8 Max #18). Ranks move as the leaderboard updates.
- Can I use gpt-oss-20b and Qwen3.8 Max with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-oss-20b" 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 gpt-oss-20b and Qwen3.8 Max from the browser chat and the API. No monthly fee.