FastMetal

Model comparison

Beam 1.0 501B A23B vs Kimi K3.1 Pro

Pricing, context window and real answers (October 2026)

Beam 1.0 501B A23B (Reflection AI) and Kimi K3.1 Pro (Moonshot), 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

Beam 1.0 501B A23Bmoonshotai logoKimi K3.1 Pro
ProviderReflection AIMoonshot
Input (per 1M tokens)$0.422$2.11
Output (per 1M tokens)$1.27$10.55
Typical cost (1,000 in + 500 out tokens × 1,000 calls)$1.06$7.39
Context window1,048,576 tokens1,048,576 tokens
Release date10/16/202610/23/2026
Input modalitiestexttext, image, video
Throughput (p50)——
Arena · overall#104 · ELO 1,436Unranked
Arena · JapaneseUnrankedUnranked
Arena · coding#71 · ELO 1,504Unranked

Prices are FastMetal's rates, before tax.

Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-22; category names mapped and ratings rounded by FastMetal.

Which should you pick?

  • On price, Beam 1.0 501B A23B: $1.27 per 1M output tokens, 88% less than Kimi K3.1 Pro.
  • 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.

Beam 1.0 501B A23B

The word “strawberry” is spelled: s - t - r - a - w - b - e - r - r - y The letter “r” appears in these positions: - s**r**awberry (1st r) - strawbe**r**ry (2nd r) - strawber**r**y (3rd r) Therefore, there are **3** r's in “strawberry.”
7.6s278 output tokens

Kimi K3.1 Pro

There are **3** ‘r’s in **“strawberry.”** 1. Write out each letter: **s – t – r – a – w – b – e – r – r – y** 2. Locate the ‘r’s: positions **3, 8, and 9**. 3. Count them: **1 + 1 + 1 = 3**.
11.3s

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…

Beam 1.0 501B A23B

The error means `users` is `undefined` when `UserList` renders, so calling `.map` on `undefined` throws. ### Common causes 1. Parent renders `<UserList />` without a `users` prop. 2. Parent passes `users={data}` where `data` is still `undefined` (e.g., fetch not resolved). 3. Destructured prop name mismatch. ### Fixes **1. Default the prop** ```js function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` **2. Guard in JSX** ```js {Array.isArray(users) && users.map(user => <li key={user.id}>{user.name}</li>)} ``` **3. Optional chaining** ```js {users?.map(user => <li key={user.id}>{user.name}</li>)} ``` Note…
12.8s414 output tokens

Kimi K3.1 Pro

## What's causing the error The error means `users` is `undefined` when the component renders, and you can't call `.map()` on `undefined`. The component itself is fine — the problem is that whatever renders `<UserList />` either isn't passing the prop, or is passing a value that isn't an array yet. The most common cause is **async data fetching**: the parent renders `UserList` before the data has loaded. ```jsx function App() { const [users, setUsers] = useState(); // ❌ undefined on first render useEffect(() => { fetch('/api/users') .then(res => res.json()) .then(setUsers); }, []); return <UserList users={users} />; // users is undefined here initially } ``` On…
36.3s

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):…

Beam 1.0 501B A23B

Here are some key issues and improvements: ### Main issues in the original - **Imports inside the function** run on every call and hurt readability. - **Bare `except:`** catches `KeyboardInterrupt`, `SystemExit`, and programming errors. - **Retries every non-200 response**, including `404`/`400`, which usually should not be retried. - **`item["active"] == True`** can raise `KeyError` and is stricter than necessary unless you truly need exact boolean equality. - **Fixed sleep and unnecessary final sleep** before returning. - **Repeated `item["name"]` / `item["id"]`** lookups are slightly slower and less clean than a comprehension. - No handling/validation for malformed JSON or non-list respo…
16.8s1927 output tokens

Kimi K3.1 Pro

The timeout and bounded retry loop are good starting points. The biggest issue is that failures—and even programming errors—are silently converted into retries and then `[]`. ### Suggested improvements - **Avoid bare `except:`**. It catches `KeyboardInterrupt`, `KeyError`, JSON/schema errors, and other bugs. Retry only expected transient network failures; let malformed responses fail visibly. - **Use a deliberate retry policy**. Retrying `401`, `403`, or `404` usually wastes time. Retry only transient statuses, use exponential backoff, and avoid sleeping after the final attempt. - **Do not use `[]` for both failure and no results**. Prefer raising the final exception so callers can disting…
560.2s

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Frequently asked questions

Which is cheaper, Beam 1.0 501B A23B or Kimi K3.1 Pro?
Per 1M output tokens, Beam 1.0 501B A23B is $1.27 and Kimi K3.1 Pro is $10.55 on FastMetal (US dollars, before tax), so Beam 1.0 501B A23B is cheaper.
How do the context windows of Beam 1.0 501B A23B and Kimi K3.1 Pro compare?
Beam 1.0 501B A23B takes 1,048,576 tokens; Kimi K3.1 Pro takes 1,048,576.
Can I use Beam 1.0 501B A23B and Kimi K3.1 Pro with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "beam-1.0" or "kimi-k3.1-pro" 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 Beam 1.0 501B A23B and Kimi K3.1 Pro from the browser chat and the API. No monthly fee.

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