Gemini 3.8 Flash vs GPT-6 Astra
Pricing, context window and real answers (September 2026)
Gemini 3.8 Flash (Google) and GPT-6 Astra (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
 Gemini 3.8 Flash |  GPT-6 Astra | |
|---|---|---|
| Provider | OpenAI | |
| Input (per 1M tokens) | ¥128.83 | ¥1,717.72 |
| Output (per 1M tokens) | ¥644.15 | ¥8,588.62 |
| Typical cost (1,000 in + 500 out tokens × 1,000 calls) | ¥451 | ¥6,012 |
| Context window | 1,048,576 tokens | 1,050,000 tokens |
| Release date | 9/2/2026 | 9/4/2026 |
| Input modalities | text, image, video, file, audio | file, image, text |
| Arena · overall | #8 · ELO 1,494 | Unranked |
| Arena · Japanese | Unranked | Unranked |
| Arena · coding | #7 · ELO 1,537 | Unranked |
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, 92% less than GPT-6 Astra.
- For long documents, GPT-6 Astra: 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-6 Astra
“strawberry” is spelled **s-t-r-a-w-b-e-r-r-y**.
The letter **r** appears in positions **3, 8, and 9**, so there are **3 r’s**.
3.8s85 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-6 Astra
The error means **`users` is `undefined` when React renders `UserList`**, so calling `users.map(...)` fails. This commonly happens when the parent doesn’t pass the prop or when data hasn’t finished loading.
### 1. Default `users` to an empty array
If an absent prop should mean “no users,” use a default value:
```jsx
function UserList({ users = [] }) {
return (
<ul>
{users.map(user => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
```
This handles a missing or `undefined` prop, but **not `null` or other non-array values**.
### 2. Check where the prop comes from
Make sure the parent passes an array. For data loaded asynchronously, initialize state to…
6.7s380 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-6 Astra
The function is compact, but its biggest issue is that **all failures silently become `[]`**, making an unavailable API indistinguishable from a successful response with no active items.
### Suggested improvements
- **Move imports to module scope** for clarity and conventional organization.
- **Avoid bare `except:`.** It catches everything, including `KeyboardInterrupt`, and hides bugs such as missing dictionary keys.
- **Retry only transient failures**, such as connection errors, timeouts, rate limiting, and selected server errors. Retrying a `401` or `404` usually won’t help.
- **Don’t sleep after the final failed attempt.** Use exponential backoff rather than a fixed delay.
- **Use desc…
19.2s965 output tokens
Frequently asked questions
- Which is cheaper, Gemini 3.8 Flash or GPT-6 Astra?
- Per 1M output tokens, Gemini 3.8 Flash is ¥644.15 and GPT-6 Astra is ¥8,588.62 on FastMetal (yen, before tax), so Gemini 3.8 Flash is cheaper.
- How do the context windows of Gemini 3.8 Flash and GPT-6 Astra compare?
- Gemini 3.8 Flash takes 1,048,576 tokens; GPT-6 Astra takes 1,050,000.
- Can I use Gemini 3.8 Flash and GPT-6 Astra with the same API key?
- Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gemini-3.8-flash" or "gpt-6-astra" 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-6 Astra from the browser chat and the API. No monthly fee.