Model comparison

Gemini 3.8 Flash vs Solar Mini 4

Pricing, context window and real answers (September 2026)

Gemini 3.8 Flash (Google) and Solar Mini 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

google logoGemini 3.8 FlashSolar Mini 4
ProviderGoogleUpstage
Input (per 1M tokens)¥134.03¥8.94
Output (per 1M tokens)¥670.13¥35.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥469¥27
Context window1,048,576 tokens524,288 tokens
Release date9/2/20269/23/2026
Input modalitiestext, image, video, file, audiotext
Throughput (p50)——
Arena · overall#9 · ELO 1,493Unranked
Arena · JapaneseUnrankedUnranked
Arena · coding#10 · ELO 1,535Unranked

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

Which should you pick?

  • On price, Solar Mini 4: ¥35.74 per 1M output tokens, 95% less than Gemini 3.8 Flash.
  • For long documents, Gemini 3.8 Flash: a 1,048,576-token context window against 524,288 for Solar Mini 4.
  • 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 3.8 Flash

There are **3** 'r's in the word "strawberry". Here is the step-by-step breakdown: 1. **Break the word into its individual letters:** * **s** (1st letter) * **t** (2nd letter) * **r** (3rd letter) — **1st 'r'** * **a** (4th letter) * **w** (5th letter) * **b** (6th letter) * **e** (7th letter) * **r** (8th letter) — **2nd 'r'** * **r** (9th letter) — **3rd 'r'** * **y** (10th letter) 2. **Count the occurrences:** * One 'r' is in the first syllable: "st**r**aw" * Two 'r's are in the second syllable: "be**rr**y" Total: **3**
3.9s562 output tokens

Solar Mini 4

Sure! Let’s count the letter **'r'** in the word **'strawberry'** step by step. **Step 1: Write out the word and its letters** `s t r a w b e r r y` **Step 2: Go through each letter one by one and check if it is 'r'** 1. `s` → not 'r' 2. `t` → not 'r' 3. `r` → **yes** (1st 'r') 4. `a` → not 'r' 5. `w` → not 'r' 6. `b` → not 'r' 7. `e` → not 'r' 8. `r` → **yes** (2nd 'r') 9. `r` → **yes** (3rd 'r') 10. `y` → not 'r' **Step 3: Tally the total** Total 'r' count = 3 **Final answer:** There are **3** letter 'r's in the word **'strawberry'**.
2.5s239 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 3.8 Flash

### The Cause This error occurs because the `users` prop is `undefined` when the component renders, and JavaScript cannot call `.map()` on `undefined`. This typically happens in two common scenarios: 1. **Asynchronous data fetching:** The parent component fetches `users` from an API. On the initial render, the data hasn't arrived yet, so `users` defaults to `undefined`. 2. **Missing prop:** The parent component forgot to pass `users` (e.g., `<UserList />` instead of `<UserList users={data} />`). --- ### How to Fix It Here are the most common ways to resolve this: #### Option 1: Provide a default parameter (Recommended) Set a default value of an empty array (`[]`) for `users`. If `users…
7.1s1003 output tokens

Solar Mini 4

This error occurs because the `users` prop being passed to your `UserList` component is `undefined` (or the component is rendered without that prop), and your code tries to call `.map()` on it. ### 🔍 Why this happens In JavaScript, `undefined.map` is not a function, so calling it throws: ``` TypeError: Cannot read properties of undefined (reading 'map') ``` This commonly happens when: - The parent component doesn't pass the `users` prop at all - The parent passes `users` as `undefined`, `null`, or a non-array value (like a promise, object, or string) - Data hasn't finished loading yet (e.g., fetched from an API asynchronously) ### ✅ How to fix it The most robust solution is to provide a…
9.2s701 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 3.8 Flash

Here is a code review of your function, broken down by issue category, followed by refactored versions. --- ### Key Issues & Areas for Improvement #### 1. Correctness & Error Handling * **Bare `except:` clause:** Catching all exceptions with a bare `except:` is dangerous. It suppresses system exits (`KeyboardInterrupt`, `SystemExit`) and masks programming bugs (like `KeyError` or `NameError`). You should catch specific exceptions, primarily `requests.RequestException`. * **Silent failure returning `[]`:** If all retries fail, returning an empty list makes it impossible for the caller to distinguish between *"the API returned 0 active items"* and *"the network is completely down"*. It is u…
15.1s2139 output tokens

Solar Mini 4

Here’s a reviewed version of your function, followed by a breakdown of the improvements: ```python import time import requests from requests.adapters import HTTPAdapter from urllib3.util.retry import Retry def get_data(url: str, retries: int = 3) -> list[dict]: """ Fetch JSON from a URL and return a list of active items with name/id. Args: url: The endpoint to request. retries: Number of retry attempts on failure. Returns: A list of dicts matching {'name': str, 'id': any} for active items. """ if retries < 1: raise ValueError("retries must be at least 1") session = requests.Session() retry_strategy = Retry( total=re…
10.8s1278 output tokens

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Frequently asked questions

Which is cheaper, Gemini 3.8 Flash or Solar Mini 4?
Per 1M output tokens, Gemini 3.8 Flash is ¥670.13 and Solar Mini 4 is ¥35.74 on FastMetal (yen, before tax), so Solar Mini 4 is cheaper.
How do the context windows of Gemini 3.8 Flash and Solar Mini 4 compare?
Gemini 3.8 Flash takes 1,048,576 tokens; Solar Mini 4 takes 524,288.
Can I use Gemini 3.8 Flash and Solar Mini 4 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.8-flash" or "solar-mini4" 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 3.8 Flash and Solar Mini 4 from the browser chat and the API. No monthly fee.

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