GPT-5.6 Sol vs gpt-oss-120b
Pricing, context window and real answers (October 2026)
GPT-5.6 Sol (OpenAI) and gpt-oss-120b (OpenAI), 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-5.6 Sol | gpt-oss-120b | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input (per 1M tokens) | $2.20 | $0.102 |
| Output (per 1M tokens) | $11.00 | $0.5035 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | $7.70 | $0.3537 |
| Context window | 1,050,000 tokens | 131,072 tokens |
| Release date | 7/9/2026 | 8/5/2025 |
| Input modalities | file, image, text | text |
| Throughput (p50) | 215 tokens/s (n=26) | 327 tokens/s (n=25) |
| Arena · overall | #20 · ELO 1,485 | #213 · ELO 1,352 |
| Arena · Japanese | #12 · ELO 1,495 | #148 · ELO 1,325 |
| Arena · coding | #13 · ELO 1,535 | #221 · ELO 1,389 |
Prices are FastMetal's rates, before tax.
Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-08; category names mapped and ratings rounded by FastMetal.
Which should you pick?
- On price, gpt-oss-120b: $0.5035 per 1M output tokens, 95% less than GPT-5.6 Sol.
- On the Overall arena board, GPT-5.6 Sol ranks higher (#20; gpt-oss-120b is #213).
- On the Japanese arena board, GPT-5.6 Sol ranks higher (#12; gpt-oss-120b is #148).
- On the Coding arena board, GPT-5.6 Sol ranks higher (#13; gpt-oss-120b is #221).
- For long documents, GPT-5.6 Sol: a 1,050,000-token context window against 131,072 for gpt-oss-120b.
- 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-5.6 Sol
“strawberry” can be split into letters:
s, t, **r**, a, w, b, e, **r**, **r**, y
The letter **r** appears **3 times**.
3.0s78 output tokens
gpt-oss-120b
**Step‑by‑step count of the letter “r” in the word “strawberry”**
1. Write out the word with each letter in order, labeling its position:
| Position | Letter |
|----------|--------|
| 1 | s |
| 2 | t |
| 3 | **r** |
| 4 | a |
| 5 | w |
| 6 | b |
| 7 | e |
| 8 | **r** |
| 9 | **r** |
|10 | y |
2. Scan the list and mark every occurrence of the letter **r**.
- Position 3 → r (first occurrence)
- Position 8 → r (second occurrence)
- Position 9 → r (third occurrence)
3. Count the marked entries: there are **3** marked positions.
**Result:** The word “strawberry” contains **3** occurrences of the letter **r**…
1.7s332 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-5.6 Sol
The error occurs because `users` is `undefined` when `UserList` renders, so JavaScript cannot call `.map()` on it. This often happens when data is loaded asynchronously or the parent does not pass the prop.
### Fix options
**1. Give `users` a default value:**
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
```
Note that this handles `undefined`, but not an explicitly passed `null`.
**2. Handle missing or invalid data explicitly:**
```jsx
function UserList({ users }) {
if (!Array.isArray(users)) {
return <p>No users available.</p>;
}
return (
<ul>
{users.m…
7.1s395 output tokens
gpt-oss-120b
### Why the `map` can’t be called
`Array.prototype.map` is a method that exists only on **arrays** (or array‑like objects).
When you see
```
TypeError: Cannot read properties of undefined (reading 'map')
at UserList (...)
```
it means that the variable you think is an array – `users` in this case – is actually **`undefined`** (or `null`).
React is trying to evaluate this line:
```jsx
{users.map(user => <li key={user.id}>{user.name}</li>)}
```
and it crashes because you can’t read `.map` from `undefined`.
---
## Common reasons `users` ends up undefined
| Reason | Typical scenario | How it shows up |
|--------|------------------|-----------------|
| **Prop not passed** | `<Use…
7.3s1610 output tokens
Code Review
Please review the following Python function and suggest improvements for readability, performance, and best practices: def get_data(url, retries=3): import requests import time for i in range(retries):…
GPT-5.6 Sol
### Issues and suggested improvements
- Move imports to module scope.
- Avoid bare `except:`; it catches programming errors and interrupts such as `KeyboardInterrupt`.
- Use `response.raise_for_status()` instead of manually checking only for `200`; other 2xx responses may also be valid.
- Retry only transient failures, such as timeouts, connection errors, `429`, and selected `5xx` responses. Retrying most `4xx` errors is not useful.
- Use exponential backoff rather than a fixed delay.
- Avoid sleeping after the final failed attempt.
- Replace `item["active"] == True` with `item.get("active") is True`.
- Use a list comprehension for the transformation.
- Add type hints and validate arguments…
33.1s1646 output tokens
gpt-oss-120b
Below is a **step‑by‑step review** of the original `get_data` implementation followed by a **refactored version** that addresses readability, performance, and modern Python best‑practice concerns.
---
## 1. What the original function does
```python
def get_data(url, retries=3):
import requests
import time
for i in range(retries):
try:
r = requests.get(url, timeout=10)
if r.status_code == 200:
data = r.json()
result = []
for item in data:
if item["active"] == True:
result.append({"name": item["name"], "id": item["id"]})
return result…
14.4s3132 output tokens
Frequently asked questions
- Which is cheaper, GPT-5.6 Sol or gpt-oss-120b?
- Per 1M output tokens, GPT-5.6 Sol is $11.00 and gpt-oss-120b is $0.5035 on FastMetal (US dollars, before tax), so gpt-oss-120b is cheaper.
- How do the context windows of GPT-5.6 Sol and gpt-oss-120b compare?
- GPT-5.6 Sol takes 1,050,000 tokens; gpt-oss-120b takes 131,072.
- Which ranks higher, GPT-5.6 Sol or gpt-oss-120b?
- GPT-5.6 Sol ranks higher on the public arena (GPT-5.6 Sol #12, gpt-oss-120b #148). Ranks move as the leaderboard updates.
- Can I use GPT-5.6 Sol and gpt-oss-120b with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-5.6-sol" or "gpt-oss-120b" 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-5.6 Sol and gpt-oss-120b from the browser chat and the API. No monthly fee.