Model comparison

Gemini 3.8 Flash vs GPT-5.6 Sol

Pricing, context window and real answers (September 2026)

Gemini 3.8 Flash (Google) and GPT-5.6 Sol (OpenAI), 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 Flashopenai logoGPT-5.6 Sol
ProviderGoogleOpenAI
Input (per 1M tokens)¥128.83¥893.5
Output (per 1M tokens)¥644.15¥5,361
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥451¥3,574
Context window1,048,576 tokens1,050,000 tokens
Release date9/2/20267/9/2026
Input modalitiestext, image, video, file, audiofile, image, text
Arena · overall#8 · ELO 1,494#17 · ELO 1,483
Arena · JapaneseUnranked#2 · ELO 1,522
Arena · coding#7 · ELO 1,537#14 · ELO 1,529

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

Which should you pick?

  • On price, Gemini 3.8 Flash: ¥644.15 per 1M output tokens, 88% less than GPT-5.6 Sol.
  • On the Overall arena board, Gemini 3.8 Flash ranks higher (#8; GPT-5.6 Sol is #17).
  • On the Coding arena board, Gemini 3.8 Flash ranks higher (#7; GPT-5.6 Sol is #14).
  • For long documents, GPT-5.6 Sol: a 1,050,000-token context window against 1,048,576 for Gemini 3.8 Flash.
  • 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

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

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

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

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

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

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Frequently asked questions

Which is cheaper, Gemini 3.8 Flash or GPT-5.6 Sol?
Per 1M output tokens, Gemini 3.8 Flash is ¥644.15 and GPT-5.6 Sol is ¥5,361 on FastMetal (yen, before tax), so Gemini 3.8 Flash is cheaper.
How do the context windows of Gemini 3.8 Flash and GPT-5.6 Sol compare?
Gemini 3.8 Flash takes 1,048,576 tokens; GPT-5.6 Sol takes 1,050,000.
Which ranks higher, Gemini 3.8 Flash or GPT-5.6 Sol?
GPT-5.6 Sol ranks higher on the public arena (Gemini 3.8 Flash #8, GPT-5.6 Sol #2). Ranks move as the leaderboard updates.
Can I use Gemini 3.8 Flash and GPT-5.6 Sol with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.8-flash" or "gpt-5.6-sol" 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 GPT-5.6 Sol from the browser chat and the API. No monthly fee.

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