FastMetal
30% off, limited timeDeepSeek V4.1 Flash 1017, run in Japan, is 30% off until December 4 (JST)See details

Model comparison

GPT-5.6 Sol vs Hy4

Pricing, context window and real answers (November 2026)

GPT-5.6 Sol (OpenAI) and Hy4 (Tencent), 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

openai logoGPT-5.6 Soltencent logoHy4
ProviderOpenAITencent
Input (per 1M tokens)$4.40$0.8799
Output (per 1M tokens)$22.00$2.64
Typical cost (1,000 in + 500 out tokens × 1,000 calls)$15.40$2.20
Context window1,050,000 tokens1,000,000 tokens
Release date7/9/202611/4/2026
Input modalitiesfile, image, texttext
Throughput (p50)213 tokens/s (n=28)—
Arena · overall#22 · ELO 1,485Unranked
Arena · Japanese#14 · ELO 1,495Unranked
Arena · coding#20 · ELO 1,533Unranked

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, 88% less than GPT-5.6 Sol.
  • For long documents, GPT-5.6 Sol: a 1,050,000-token context window against 1,000,000 for Hy4.
  • 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

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

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

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

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

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

Compare on more prompts →

Frequently asked questions

Which is cheaper, GPT-5.6 Sol or Hy4?
Per 1M output tokens, GPT-5.6 Sol is $22.00 and Hy4 is $2.64 on FastMetal (US dollars, before tax), so Hy4 is cheaper.
How do the context windows of GPT-5.6 Sol and Hy4 compare?
GPT-5.6 Sol takes 1,050,000 tokens; Hy4 takes 1,000,000.
Can I use GPT-5.6 Sol and Hy4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-5.6-sol" or "hy4" 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 Hy4 from the browser chat and the API. No monthly fee.

Create a free accountTry GPT-5.6 Sol in chatTry Hy4 in chat

More comparisons with GPT-5.6 Sol

More comparisons with Hy4