Model comparison

Gemini 3.7 Flash vs Kimi K3

Pricing, context window and real answers (August 2026)

Gemini 3.7 Flash (Google) and Kimi K3 (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

google logoGemini 3.7 Flashmoonshotai logoKimi K3
ProviderGoogleMoonshot
Input (per 1M tokens)¥134.03¥536.1
Output (per 1M tokens)¥670.13¥2,680.5
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥469¥1,876
Context window1,048,576 tokens1,048,576 tokens
Release date8/13/20267/16/2026
Input modalitiestext, image, video, file, audiotext, image
Arena · overallUnranked#11 · ELO 1,486
Arena · JapaneseUnrankedUnranked
Arena · codingUnranked#8 · ELO 1,530

Prices are FastMetal's yen rates before tax. Arena ranks are as of the latest leaderboard scrape.

Which should you pick?

  • On price, Gemini 3.7 Flash: ¥670.13 per 1M output tokens, 75% less than Kimi K3.
  • 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.

Gemini 3.7 Flash

There are **3** 'r's in the word "strawberry". ### Step-by-step reasoning: 1. **Break down the word into individual letters:** * 1st letter: **s** * 2nd letter: **t** * 3rd letter: **r** *(1st 'r')* * 4th letter: **a** * 5th letter: **w** * 6th letter: **b** * 7th letter: **e** * 8th letter: **r** *(2nd 'r')* * 9th letter: **r** *(3rd 'r')* * 10th letter: **y** 2. **Identify the positions of 'r':** * The 3rd letter is an **r** (in "st**r**aw"). * The 8th letter is an **r** (in "be**r**ry"). * The 9th letter is an **r** (in "ber**r**y"). 3. **Total count:** 1 + 1 + 1 = **3**.
4.5s530 output tokens

Kimi K3

# Counting the 'r's in "strawberry" **Step 1: Write out each letter with its position** | Position | Letter | |----------|--------| | 1 | s | | 2 | t | | 3 | **r** ✓ | | 4 | a | | 5 | w | | 6 | b | | 7 | e | | 8 | **r** ✓ | | 9 | **r** ✓ | | 10 | y | **Step 2: Identify each 'r'** - Position 3: the 'r' in "st**r**" - Position 8: the first 'r' in "be**r**ry" - Position 9: the second 'r' in "ber**r**y" **Step 3: Verify by splitting the word** "Strawberry" = "straw" + "berry" - "straw" contains **1** r - "berry" contains **2** r's **Answer: There are 3 r's in "strawberry."** 🍓
12.2s594 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…

Gemini 3.7 Flash

### Why This Error Happens This error occurs because the `users` prop is `undefined` when the component renders. Since `map` is an Array method, calling `undefined.map()` causes JavaScript to throw a `TypeError`. This usually happens when: 1. Data is being fetched asynchronously (e.g., via `fetch` or `axios`), and the component renders **before** the data has arrived. 2. The parent component forgot to pass the `users` prop (`<UserList />`). 3. The initial state in the parent component was initialized as `undefined` (e.g., `const [users, setUsers] = useState()`). --- ### How to Fix It Here are the best ways to fix it, depending on your use case: #### Solution 1: Default Parameter (Recom…
9.9s1355 output tokens

Kimi K3

## What's causing it The error means `users` is `undefined` when the component renders — `.map()` only exists on arrays, so calling it on `undefined` throws. Your component code is fine; the problem is **upstream**: whatever renders `<UserList />` isn't passing a valid array. The most common culprit is **async data fetching with uninitialized state** in the parent: ```jsx function App() { const [users, setUsers] = useState(); // ← undefined! useEffect(() => { fetch('/api/users') .then(res => res.json()) .then(setUsers); }, []); return <UserList users={users} />; // undefined on first render } ``` The component renders *before* the fetch resolves, so `users` is `…
47.5s1756 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):…

Gemini 3.7 Flash

Here is a detailed review of your function, followed by refactored versions. --- ### Key Issues & Areas for Improvement 1. **Imports inside the function (PEP 8):** Imports should be placed at the top of the file, not inside a function, to avoid repeated import overhead and improve readability. 2. **Bare `except:` clause (Anti-pattern):** Catching everything with `except:` intercepts `KeyboardInterrupt`, `SystemExit`, and memory errors, making debugging difficult. Catch specific exceptions like `requests.RequestException` and `ValueError` (for JSON decoding). 3. **Retrying on non-retryable errors:** A status code like `404 Not Found` or `401 Unauthorized` will never succeed on a…
13.2s2117 output tokens

Kimi K3

This works, but there are several issues worth addressing. Here's a breakdown, followed by an improved version. ## Issues ### Correctness & best practices 1. **Bare `except:`** — catches *everything*, including `KeyboardInterrupt` and programming bugs like `KeyError` on a malformed item (which then get pointlessly retried). Catch `requests.RequestException` specifically. 2. **Silent failures** — errors are swallowed with no logging, and returning `[]` makes "API is down" indistinguishable from "no active items." At minimum, log; ideally, raise after the final attempt. 3. **Retrying non-retryable errors** — a 400/401/404 will never succeed on retry, but the code sleeps and retries anyway. O…
57.6s8060 output tokens

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Frequently asked questions

Which is cheaper, Gemini 3.7 Flash or Kimi K3?
Per 1M output tokens, Gemini 3.7 Flash is ¥670.13 and Kimi K3 is ¥2,680.5 on FastMetal (yen, before tax), so Gemini 3.7 Flash is cheaper.
How do the context windows of Gemini 3.7 Flash and Kimi K3 compare?
Gemini 3.7 Flash takes 1,048,576 tokens; Kimi K3 takes 1,048,576.
Can I use Gemini 3.7 Flash and Kimi K3 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.7-flash" or "kimi-k3" 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 Gemini 3.7 Flash and Kimi K3 from the browser chat and the API. No monthly fee.

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