Model comparison

DeepSeek V4 Flash vs Inkling

Pricing, context window and real answers (August 2026)

DeepSeek V4 Flash (DeepSeek) 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

deepseek logoDeepSeek V4 FlashInkling
ProviderDeepSeekThinkingmachines
Input (per 1M tokens)¥16.08¥178.7
Output (per 1M tokens)¥32.17¥723.74
Typical cost (1,000 in + 500 out tokens × 1,000 calls)¥32¥541
Context window1,048,576 tokens524,288 tokens
Release date4/24/20267/17/2026
Input modalitiestexttext, image, audio
Arena · overall#79 · ELO 1,436#71 · ELO 1,443
Arena · Japanese#67 · ELO 1,390Unranked
Arena · coding#80 · ELO 1,484#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, DeepSeek V4 Flash: ¥32.17 per 1M output tokens, 96% less than Inkling.
  • On the Overall arena board, Inkling ranks higher (#71; DeepSeek V4 Flash is #79).
  • On the Coding arena board, Inkling ranks higher (#64; DeepSeek V4 Flash is #80).
  • For long documents, DeepSeek V4 Flash: a 1,048,576-token context window against 524,288 for Inkling.
  • 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.

DeepSeek V4 Flash

The word "strawberry" is spelled as s-t-r-a-w-b-e-r-r-y. I go through each letter: s (no), t (no), r (yes, first), a (no), w (no), b (no), e (no), r (yes, second), r (yes, third), y (no). Thus, there are three 'r's.
3.9s251 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…

DeepSeek V4 Flash

The error occurs because `users` is `undefined` when the component tries to call `.map()` on it. ## Why this happens Your component expects `users` to be an array, but it's receiving `undefined` as a prop. This typically happens when: 1. The parent component doesn't pass the `users` prop 2. The data fetching hasn't completed yet (async data loading) 3. The API response is missing the expected data structure ## How to fix it ### Option 1: Default prop value (Recommended for initial state) ```jsx function UserList({ users = [] }) { return ( <ul> {users.map(user => <li key={user.id}>{user.name}</li>)} </ul> ); } ``` ### Option 2: Guard clause (More explicit) ```jsx func…
6.3s422 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):…

DeepSeek V4 Flash

Here's a comprehensive review with suggested improvements: ## Issues Identified: 1. **Import at wrong location** - Imports inside functions are inefficient and non-standard 2. **Bare `except:` clause** - Catches all exceptions including `KeyboardInterrupt`, `SystemExit` 3. **Missing error handling granularity** - Should distinguish between retryable and non-retryable errors 4. **Duplicate sleep logic** - Same sleep in `else` and `except` blocks 5. **Unnecessary variable** - `data` is only used once 6. **Inefficient list building** - Manual loop instead of list comprehension 7. **Hardcoded error message** - No logging or error context 8. **Missing type hints** - No type annotations 9. **Fun…
12.6s987 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, DeepSeek V4 Flash or Inkling?
Per 1M output tokens, DeepSeek V4 Flash is ¥32.17 and Inkling is ¥723.74 on FastMetal (yen, before tax), so DeepSeek V4 Flash is cheaper.
How do the context windows of DeepSeek V4 Flash and Inkling compare?
DeepSeek V4 Flash takes 1,048,576 tokens; Inkling takes 524,288.
Which ranks higher, DeepSeek V4 Flash or Inkling?
DeepSeek V4 Flash ranks higher on the public arena (DeepSeek V4 Flash #67, Inkling #71). Ranks move as the leaderboard updates.
Can I use DeepSeek V4 Flash and Inkling with the same API key?
Yes. On FastMetal's OpenAI-compatible endpoint, switch by passing "deepseek-v4-flash" 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 DeepSeek V4 Flash and Inkling from the browser chat and the API. No monthly fee.

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