Model comparison

GPT-6 Astra vs gpt-oss-120b

Pricing, context window and real answers (September 2026)

GPT-6 Astra (OpenAI) and gpt-oss-120b (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

openai logoGPT-6 Astraopenai logogpt-oss-120b
ProviderOpenAIOpenAI
Input (per 1M tokens)¥1,717.72¥16
Output (per 1M tokens)¥8,588.62¥79
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥6,012¥56
Context window1,050,000 tokens131,072 tokens
Release date9/4/20268/5/2025
Input modalitiesfile, image, texttext
Arena · overallUnranked#200 · ELO 1,352
Arena · JapaneseUnranked#132 · ELO 1,328
Arena · codingUnranked#206 · ELO 1,391

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

Which should you pick?

  • On price, gpt-oss-120b: ¥79 per 1M output tokens, 99% less than GPT-6 Astra.
  • For long documents, GPT-6 Astra: a 1,050,000-token context window against 131,072 for gpt-oss-120b.
  • 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-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

gpt-oss-120b

**Step‑by‑step count of the letter “r” in the word “strawberry”** 1. Write out the word with each letter in order, labeling its position: | Position | Letter | |----------|--------| | 1 | s | | 2 | t | | 3 | **r** | | 4 | a | | 5 | w | | 6 | b | | 7 | e | | 8 | **r** | | 9 | **r** | |10 | y | 2. Scan the list and mark every occurrence of the letter **r**. - Position 3 → r (first occurrence) - Position 8 → r (second occurrence) - Position 9 → r (third occurrence) 3. Count the marked entries: there are **3** marked positions. **Result:** The word “strawberry” contains **3** occurrences of the letter **r**…
1.7s332 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-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

gpt-oss-120b

### Why the `map` can’t be called `Array.prototype.map` is a method that exists only on **arrays** (or array‑like objects). When you see ``` TypeError: Cannot read properties of undefined (reading 'map') at UserList (...) ``` it means that the variable you think is an array – `users` in this case – is actually **`undefined`** (or `null`). React is trying to evaluate this line: ```jsx {users.map(user => <li key={user.id}>{user.name}</li>)} ``` and it crashes because you can’t read `.map` from `undefined`. --- ## Common reasons `users` ends up undefined | Reason | Typical scenario | How it shows up | |--------|------------------|-----------------| | **Prop not passed** | `<Use…
7.3s1610 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-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

gpt-oss-120b

Below is a **step‑by‑step review** of the original `get_data` implementation followed by a **refactored version** that addresses readability, performance, and modern Python best‑practice concerns. --- ## 1. What the original function does ```python def get_data(url, retries=3): import requests import time for i in range(retries): try: r = requests.get(url, timeout=10) if r.status_code == 200: data = r.json() result = [] for item in data: if item["active"] == True: result.append({"name": item["name"], "id": item["id"]}) return result…
14.4s3132 output tokens

Compare on more prompts →

Frequently asked questions

Which is cheaper, GPT-6 Astra or gpt-oss-120b?
Per 1M output tokens, GPT-6 Astra is ¥8,588.62 and gpt-oss-120b is ¥79 on FastMetal (yen, before tax), so gpt-oss-120b is cheaper.
How do the context windows of GPT-6 Astra and gpt-oss-120b compare?
GPT-6 Astra takes 1,050,000 tokens; gpt-oss-120b takes 131,072.
Can I use GPT-6 Astra and gpt-oss-120b with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-astra" or "gpt-oss-120b" 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-6 Astra and gpt-oss-120b from the browser chat and the API. No monthly fee.

More comparisons with GPT-6 Astra

More comparisons with gpt-oss-120b