Model comparison

GPT-6 Astra vs Kimi K2.6

Pricing, context window and real answers (September 2026)

GPT-6 Astra (OpenAI) and Kimi K2.6 (Moonshot), 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 Astramoonshotai logoKimi K2.6
ProviderOpenAIMoonshot
Input (per 1M tokens)¥1,717.72¥169.77
Output (per 1M tokens)¥8,588.62¥714.8
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥6,012¥527
Context window1,050,000 tokens262,144 tokens
Release date9/4/20264/20/2026
Input modalitiesfile, image, texttext, image
Arena · overallUnranked#50 · ELO 1,461
Arena · JapaneseUnranked#37 · ELO 1,444
Arena · codingUnranked#36 · ELO 1,514

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

Which should you pick?

  • On price, Kimi K2.6: ¥714.8 per 1M output tokens, 92% less than GPT-6 Astra.
  • For long documents, GPT-6 Astra: a 1,050,000-token context window against 262,144 for Kimi K2.6.
  • 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

Kimi K2.6

Here is the step-by-step count: **Step 1:** Write out the word and number each letter. 1. s 2. t 3. **r** ← 1st 'r' 4. a 5. w 6. b 7. e 8. **r** ← 2nd 'r' 9. **r** ← 3rd 'r' 10. y **Step 2:** Identify the positions containing the letter 'r'. - The 3rd letter is **r** - The 8th letter is **r** - The 9th letter is **r** **Step 3:** Tally the total. There are **3** letter 'r's in "strawberry".
4.5s352 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

Kimi K2.6

The error occurs because `users` is `undefined` when your component renders. The `.map()` method only works on arrays, so calling it on `undefined` throws this error. This usually happens when: - The parent component hasn't finished fetching data yet - The `users` prop isn't being passed at all - The prop is misspelled in the parent component ## Quick Fix Set a **default value** for the `users` prop: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` ## Alternative Fixes **Optional chaining** (renders nothing if undefined): ```jsx {users?.map(user => <li key={user.id}>{user.name}</li>)} ```…
71.8s864 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

Kimi K2.6

Here is a refactored version followed by a breakdown of the improvements. ### Refactored Function ```python import logging import time from typing import Any import requests logger = logging.getLogger(__name__) def fetch_active_items( url: str, *, retries: int = 3, timeout: float = 10.0, backoff: float = 2.0, ) -> list[dict[str, Any]]: """Fetch active items from an API endpoint with retry logic. Args: url: The API endpoint URL. retries: Number of retry attempts for transient failures. timeout: HTTP request timeout in seconds. backoff: Base delay in seconds between retries (linear backoff). Returns: A list of activ…
17.9s4061 output tokens

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Frequently asked questions

Which is cheaper, GPT-6 Astra or Kimi K2.6?
Per 1M output tokens, GPT-6 Astra is ¥8,588.62 and Kimi K2.6 is ¥714.8 on FastMetal (yen, before tax), so Kimi K2.6 is cheaper.
How do the context windows of GPT-6 Astra and Kimi K2.6 compare?
GPT-6 Astra takes 1,050,000 tokens; Kimi K2.6 takes 262,144.
Can I use GPT-6 Astra and Kimi K2.6 with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-6-astra" or "kimi-k2.6" 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 Kimi K2.6 from the browser chat and the API. No monthly fee.

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