Claude Sonnet 5 vs MiniMax M3.1 Flash
Pricing, context window and real answers (October 2026)
Claude Sonnet 5 (Anthropic) and MiniMax M3.1 Flash (MiniMax), 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 Sonnet 5 |  MiniMax M3.1 Flash | |
|---|---|---|
| Provider | Anthropic | MiniMax |
| Input (per 1M tokens) | $2.11 | $0.1583 |
| Output (per 1M tokens) | $10.55 | $0.633 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | $7.39 | $0.4748 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Release date | 6/30/2026 | 10/19/2026 |
| Input modalities | text, image, file | text, image |
| Throughput (p50) | 513 tokens/s (n=26) | — |
| Arena · overall | #36 · ELO 1,475 | Unranked |
| Arena · Japanese | #41 · ELO 1,445 | Unranked |
| Arena · coding | #21 · ELO 1,530 | Unranked |
Prices are FastMetal's rates, before tax.
Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-15; category names mapped and ratings rounded by FastMetal.
Which should you pick?
- On price, MiniMax M3.1 Flash: $0.633 per 1M output tokens, 94% less than Claude Sonnet 5.
- For long documents, MiniMax M3.1 Flash: a 1,048,576-token context window against 1,000,000 for Claude Sonnet 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 Sonnet 5
# Counting 'r's in "strawberry"
**Step 1: Spell out the word letter by letter**
s - t - r - a - w - b - e - r - r - y
**Step 2: Number each letter position**
| Position | Letter |
|----------|--------|
| 1 | s |
| 2 | t |
| 3 | **r** |
| 4 | a |
| 5 | w |
| 6 | b |
| 7 | e |
| 8 | **r** |
| 9 | **r** |
| 10 | y |
**Step 3: Identify and count the 'r's**
- Position 3: **r** ✓ (1st r)
- Position 8: **r** ✓ (2nd r)
- Position 9: **r** ✓ (3rd r)
**Answer: There are 3 r's in "strawberry"**
5.9s405 output tokens
MiniMax M3.1 Flash
1. Spell **strawberry**:
**s – t – r – a – w – b – e – r – r – y**
2. Count the letter **r**: it appears at positions **3, 8, and 9**.
**Total: 3 “r”s.**
3.0s193 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 Sonnet 5
# Root Cause
The `UserList` component receives `users` as a prop, but at the time it's rendered, `users` is `undefined` — not an empty array, but literally missing. When your code tries to call `.map()` on `undefined`, JavaScript throws that `TypeError`.
This typically happens when:
- The parent component hasn't fetched the data yet (e.g., an API call is still in progress)
- The prop name doesn't match what's being passed down (typo)
- The data source (API/state) genuinely returns `undefined` in some case
# Fixes
**1. Add a default prop value (quick fix)**
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => <li key={user.id}>{user.name}</li>)}
</u…
8.8s750 output tokens
MiniMax M3.1 Flash
The error occurs because `users` is `undefined` when `UserList` renders. Calling `.map()` on `undefined` causes the `TypeError`.
This commonly happens when:
- `<UserList />` is rendered without passing the `users` prop.
- The prop has a different name, such as `user`.
- Data is still loading and the parent initializes its state as `undefined`.
- An API response is accessed before it exists.
### Immediate fix
Provide a default empty array:
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
```
Then pass the actual data from the parent:
```jsx
const [users, setUsers] = useState([…
7.3s744 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):…
Claude Sonnet 5
## Review of `get_data` Function
Here's an improved version followed by an explanation of the changes:
```python
import logging
import time
from typing import Any
import requests
logger = logging.getLogger(__name__)
def get_data(
url: str,
retries: int = 3,
timeout: float = 10.0,
backoff_factor: float = 2.0,
) -> list[dict[str, Any]]:
"""
Fetch active items from the given URL.
Args:
url: The endpoint to fetch data from.
retries: Number of attempts before giving up.
timeout: Request timeout in seconds.
backoff_factor: Multiplier for exponential backoff between retries.
Returns:
A list of dicts with "name" and "id"…
14.0s1299 output tokens
MiniMax M3.1 Flash
The function is understandable, but it has a few important issues:
- `except:` catches programming errors such as `KeyError`, `TypeError`, and even `KeyboardInterrupt`.
- Every non-200 response is retried, including permanent failures such as 400, 401, and 404.
- It sleeps after the final failed attempt.
- Returning `[]` makes a failed request indistinguishable from a successful response containing no active records.
- A fixed delay can cause clients to retry simultaneously; exponential backoff and `Retry-After` are preferable.
- `item["active"] == True` should be `item.get("active") is True` if the API contract says it is a JSON boolean.
- A `Session` can reuse connections, while `requests…
146.5s
Frequently asked questions
- Which is cheaper, Claude Sonnet 5 or MiniMax M3.1 Flash?
- Per 1M output tokens, Claude Sonnet 5 is $10.55 and MiniMax M3.1 Flash is $0.633 on FastMetal (US dollars, before tax), so MiniMax M3.1 Flash is cheaper.
- How do the context windows of Claude Sonnet 5 and MiniMax M3.1 Flash compare?
- Claude Sonnet 5 takes 1,000,000 tokens; MiniMax M3.1 Flash takes 1,048,576.
- Can I use Claude Sonnet 5 and MiniMax M3.1 Flash with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "anthropic-claude-sonnet-5" or "minimax-m3.1-flash" 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 Sonnet 5 and MiniMax M3.1 Flash from the browser chat and the API. No monthly fee.