Model comparison

Hy4 vs Kimi K2.6

Pricing, context window and real answers (November 2026)

Hy4 (Tencent) and Kimi K2.6 (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

tencent logoHy4moonshotai logoKimi K2.6
ProviderTencentMoonshot
Input (per 1M tokens)$0.8799$0.7913
Output (per 1M tokens)$2.64$3.70
Typical cost (1,000 in + 500 out tokens × 1,000 calls)$2.20$2.64
Context window1,000,000 tokens262,144 tokens
Release date11/4/20264/20/2026
Input modalitiestexttext, image
Throughput (p50)—33 tokens/s (n=18)
Arena · overallUnranked#60 · ELO 1,461
Arena · JapaneseUnranked#49 · ELO 1,440
Arena · codingUnranked#45 · ELO 1,516

Prices are FastMetal's rates, before tax.

Rankings: LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, snapshot 2026-10-28; category names mapped and ratings rounded by FastMetal.

Which should you pick?

  • On price, Hy4: $2.64 per 1M output tokens, 29% less than Kimi K2.6.
  • For long documents, Hy4: a 1,000,000-token context window against 262,144 for Kimi K2.6.
  • 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.

Hy4

The word **“strawberry”** is spelled: **s t r a w b e r r y** Step by step: 1. Check each letter: s, t, **r**, a, w, b, e, **r**, **r**, y 2. Mark the **r**’s: one after **t**, and two near the end before **y**. 3. Count them: 1 + 1 + 1 = **3** So, there are **3** ‘r’s in **“strawberry”**.
4.2s343 output tokens

Kimi K2.6

Here is the step-by-step count: **Step 1:** Write out the word and number each letter. 1. s 2. t 3. **r** ← 1st 'r' 4. a 5. w 6. b 7. e 8. **r** ← 2nd 'r' 9. **r** ← 3rd 'r' 10. y **Step 2:** Identify the positions containing the letter 'r'. - The 3rd letter is **r** - The 8th letter is **r** - The 9th letter is **r** **Step 3:** Tally the total. There are **3** letter 'r's in "strawberry".
4.5s352 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…

Hy4

The error is caused by this line: ```js {users.map(user => <li key={user.id}>{user.name}</li>)} ``` At render time, `users` is `undefined`. Since `.map()` only exists on arrays, JavaScript tries to read `map` from `undefined` and throws: ```txt Cannot read properties of undefined (reading 'map') ``` Even though this is in a Node.js app, this specific error is happening during React rendering, likely server-side rendering or a Node-based build/render process. Common causes: 1. The parent component is not passing `users`. 2. The prop name is misspelled. 3. `users` comes from async data and is `undefined` on the first render. 4. Your API returns something like `{ users: [...] }`, but you…
20.3s1951 output tokens

Kimi K2.6

The error occurs because `users` is `undefined` when your component renders. The `.map()` method only works on arrays, so calling it on `undefined` throws this error. This usually happens when: - The parent component hasn't finished fetching data yet - The `users` prop isn't being passed at all - The prop is misspelled in the parent component ## Quick Fix Set a **default value** for the `users` prop: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` ## Alternative Fixes **Optional chaining** (renders nothing if undefined): ```jsx {users?.map(user => <li key={user.id}>{user.name}</li>)} ```…
71.8s864 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):…

Hy4

Here are the main improvement areas, followed by a possible rewrite. ## Key issues ### Readability / style - Move imports to the top of the module. - Use descriptive names: `response` instead of `r`, `attempt` instead of `i`. - `if item["active"] == True:` should be `if item.get("active") is True:` or simply `if item.get("active"):`, depending on intent. - The filtering loop can be a list comprehension. - Add type hints and a docstring. ### Performance - Repeated imports are cached by Python, so not a major cost, but top-level imports are cleaner. - Avoid sleeping after the final failed attempt. - Use `requests.Session` for connection pooling if this function may be called repeatedly or i…
110.2s10761 output tokens

Kimi K2.6

Here is a refactored version followed by a breakdown of the improvements. ### Refactored Function ```python import logging import time from typing import Any import requests logger = logging.getLogger(__name__) def fetch_active_items( url: str, *, retries: int = 3, timeout: float = 10.0, backoff: float = 2.0, ) -> list[dict[str, Any]]: """Fetch active items from an API endpoint with retry logic. Args: url: The API endpoint URL. retries: Number of retry attempts for transient failures. timeout: HTTP request timeout in seconds. backoff: Base delay in seconds between retries (linear backoff). Returns: A list of activ…
17.9s4061 output tokens

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Frequently asked questions

Which is cheaper, Hy4 or Kimi K2.6?
Per 1M output tokens, Hy4 is $2.64 and Kimi K2.6 is $3.70 on FastMetal (US dollars, before tax), so Hy4 is cheaper.
How do the context windows of Hy4 and Kimi K2.6 compare?
Hy4 takes 1,000,000 tokens; Kimi K2.6 takes 262,144.
Can I use Hy4 and Kimi K2.6 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "hy4" or "kimi-k2.6" 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 Hy4 and Kimi K2.6 from the browser chat and the API. No monthly fee.

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