Model comparison

gpt-oss-120b vs Inkling

Pricing, context window and real answers (August 2026)

gpt-oss-120b (OpenAI) and Inkling (Thinkingmachines), 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-oss-120bInkling
ProviderOpenAIThinkingmachines
Input (per 1M tokens)¥16¥178.7
Output (per 1M tokens)¥79¥723.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥56¥541
Context window131,072 tokens524,288 tokens
Release date8/5/20257/17/2026
Input modalitiestexttext, image, audio
Arena · overall#186 · ELO 1,352#71 · ELO 1,443
Arena · Japanese#123 · ELO 1,320Unranked
Arena · coding#190 · ELO 1,390#64 · ELO 1,496

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, 89% less than Inkling.
  • On the Overall arena board, Inkling ranks higher (#71; gpt-oss-120b is #186).
  • On the Coding arena board, Inkling ranks higher (#64; gpt-oss-120b is #190).
  • For long documents, Inkling: a 524,288-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-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

Inkling

Let's break down the word **"strawberry"** letter by 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** So the spelling is: s-t-**r**-a-w-b-e-**r**-**r**-y Counting them up: - One 'r' in "str" (the 3rd letter) - Two 'r's in "berry" (the 8th and 9th letters) **Total: 3 'r's** in "strawberry".**
2.4s417 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-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

Inkling

The error occurs because `users` is `undefined` when `UserList` renders, so `users.map` fails. This usually happens when: - The parent doesn't pass the prop (`<UserList />` instead of `<UserList users={...} />`) - Data is still loading (e.g., API hasn't returned yet) ## Quick Fix Provide a default empty array so `.map` always has an array to work with: ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` Alternatively, guard against undefined explicitly: ```jsx function UserList({ users }) { if (!users) return null; // or a loading state return ( <ul> {users.map(user => <li key={…
4.9s585 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-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

Inkling

Here is a review with an improved version followed by explanations. ### Issues in the original - **Imports inside the function**: Re-importing on every call is inefficient. - **Bare `except:`**: Catches `SystemExit`, `KeyboardInterrupt`, etc. - **Silent failures**: No logging; errors disappear. - **Magic numbers**: `10`, `2`, `200` are hard-coded. - **Data validation missing**: Assumes `data` is a list and every item has `"active"`, `"name"`, and `"id"` (will crash with `KeyError`). - **Performance**: Uses `.append()` in a loop instead of a list comprehension. - **Ambiguous return**: `[]` means both "success with no results" and "total failure". ### Improved version ```python import loggi…
54.1s5649 output tokens

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Frequently asked questions

Which is cheaper, gpt-oss-120b or Inkling?
Per 1M output tokens, gpt-oss-120b is ¥79 and Inkling is ¥723.74 on FastMetal (yen, before tax), so gpt-oss-120b is cheaper.
How do the context windows of gpt-oss-120b and Inkling compare?
gpt-oss-120b takes 131,072 tokens; Inkling takes 524,288.
Which ranks higher, gpt-oss-120b or Inkling?
Inkling ranks higher on the public arena (gpt-oss-120b #123, Inkling #71). Ranks move as the leaderboard updates.
Can I use gpt-oss-120b and Inkling with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "gpt-oss-120b" or "inkling" 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-oss-120b and Inkling from the browser chat and the API. No monthly fee.

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