Model comparison

LLM-jp-3.1 8x13B instruct4 vs Solar Pro 4

Pricing, context window and real answers (August 2026)

LLM-jp-3.1 8x13B instruct4 (Llm Jp) and Solar Pro 4 (Upstage), 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

LLM-jp-3.1 8x13B instruct4Solar Pro 4
ProviderLlm JpUpstage
Input (per 1M tokens)¥16¥5.28
Output (per 1M tokens)¥79¥21.11
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥56¥16
Context window4,096 tokens524,288 tokens
Release date3/21/20268/10/2026
Input modalitiestexttext
Arena · overallUnranked#173 · ELO 1,376
Arena · JapaneseUnrankedUnranked
Arena · codingUnranked#140 · ELO 1,448

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

Which should you pick?

  • On price, Solar Pro 4: ¥21.11 per 1M output tokens, 73% less than LLM-jp-3.1 8x13B instruct4.
  • For long documents, Solar Pro 4: a 524,288-token context window against 4,096 for LLM-jp-3.1 8x13B instruct4.
  • 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.

LLM-jp-3.1 8x13B instruct4

To count the number of 'r's in the word 'strawberry', follow these steps: 1. Identify the word: The word we are examining is 'strawberry'. 2. Understand the task: We need to find and count all occurrences of the letter 'r' in this word. 3. Begin with the first letter: The first letter is 's', which is not 'r', so we move on to the next letter. 4. Proceed to the second letter: The second letter is 't', which is also not 'r', so we continue to the third letter. 5. Reach the third letter: The third letter is 'r'. We have found one 'r'. 6. Continue to the fourth letter: The fourth letter is 'a', which is not 'r', so we move on to the fifth letter. 7. Examine the fifth letter: The fifth letter i…
4.0s400 output tokens

Solar Pro 4

The word "strawberry" contains **3** 'r's. Here's the step-by-step breakdown: 1. **Spell out the word explicitly** to isolate each letter: `s - t - r - a - w - b - e - r - r - y` 2. **Scan through the letters in order** and count every instance of the lowercase letter `r`: - `s` → 0 - `t` → 0 - `r` → **1** - `a` → 0 - `w` → 0 - `b` → 0 - `e` → 0 - `r` → **2** - `r` → **3** - `y` → 0 3. **Total the count**: The three `r`s appear at positions 3, 8, and 9 in the 10-letter word. **Final count: 3**
11.4s215 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…

LLM-jp-3.1 8x13B instruct4

The error TypeError: Cannot read properties of undefined (reading 'map') suggests that the 'users' argument passed to the UserList component is undefined or does not have a 'map' method. The cause of the problem may be that the users variable is not being passed correctly or is not defined in the parent component. Check the props being passed to the UserList component to ensure that they are defined and contain the expected data. To fix the issue, you can add some error handling and debugging to your component. Try logging the users variable to the console to verify that it is not undefined: ```jsx function UserList({ users }) { console.log("Users:", users); if (!users) { return <…
3.0s279 output tokens

Solar Pro 4

### What's Causing the Error The error `TypeError: Cannot read properties of undefined (reading 'map')` means that the `users` prop being passed to your `UserList` component is `undefined`. Since you're calling `.map()` directly on it, JavaScript throws an error because `undefined` doesn't have a `map` method. This typically happens when: - The parent component hasn't passed the `users` prop - The prop is still loading (e.g., from an API call) - The prop is conditionally undefined --- ### How to Fix It You have a few options to handle this safely: #### ✅ Option 1: Add a Default Prop Value (Recommended) Provide a fallback empty array so `.map()` always has something to work with: ```j…
24.7s539 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):…

LLM-jp-3.1 8x13B instruct4

The provided Python function aims to get data from a URL using the requests library, filter out specific items based on their "active" field, and return the result. Here are some suggestions to improve readability, performance, and adherence to best practices: 1. Configure the linter (e.g., flake8 or pylint) to ensure code quality and enforce a consistent coding style. 2. Use type hints to improve readability and maintainability. 3. Use context managers (with statement) for handling requests: 4. Rewrite the function using a more functional programming style: Here's the improved version of the function: ```python import requests import time from typing import List, Dict, Any def get_da…
3.9s406 output tokens

Solar Pro 4

Here’s a breakdown of the issues in the original function, followed by a refactored version and a detailed explanation of the improvements. ### 🔍 Key Issues in the Original Code | Area | Problem | |------|---------| | **Import organization** | `import` inside the function is evaluated on every call. Imports should live at the top of the module. | | **Exception handling** | Bare `except:` catches `SystemExit`, `KeyboardInterrupt`, and other fatal errors. Always catch specific exceptions (`requests.RequestException`). | | **Loose equality** | `== True` is redundant and can cause subtle bugs. Use `if item["active"]:` or `.get()`. | | **HTTP status handling** | Calling `.json()` only on `200`…
17.5s1172 output tokens

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Frequently asked questions

Which is cheaper, LLM-jp-3.1 8x13B instruct4 or Solar Pro 4?
Per 1M output tokens, LLM-jp-3.1 8x13B instruct4 is ¥79 and Solar Pro 4 is ¥21.11 on FastMetal (yen, before tax), so Solar Pro 4 is cheaper.
How do the context windows of LLM-jp-3.1 8x13B instruct4 and Solar Pro 4 compare?
LLM-jp-3.1 8x13B instruct4 takes 4,096 tokens; Solar Pro 4 takes 524,288.
Can I use LLM-jp-3.1 8x13B instruct4 and Solar Pro 4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "llm-jp-3.1-8x13b-instruct4" or "solar-pro4" 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 LLM-jp-3.1 8x13B instruct4 and Solar Pro 4 from the browser chat and the API. No monthly fee.

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