Software Alternatives, Accelerators & Startups

Rectangle VS APIMaster

Compare Rectangle VS APIMaster and see what are their differences

Rectangle logo Rectangle

Window management app based on Spectacle, written in Swift.

APIMaster logo APIMaster

AI API marketplace: buy OpenAI, Claude & DeepSeek keys at up to 90% off. Fingerprint-verified providers โ€” no fake models.
  • Rectangle Landing page
    Landing page //
    2023-05-20
  • APIMaster API Key market
    API Key market //
    2026-06-15

APIMaster is an AI API marketplace offering OpenAI, Claude, and DeepSeek API keys at up to 90% off official pricing. One API key gives you access to all major models with OpenAI-compatible endpoints โ€” plug directly into Cursor, Claude Code, or any SDK.

Every provider is fingerprint-verified weekly to ensure you're getting the real model. Supports PayPal, USDT, and ePay. No subscription, pay-as-you-go from $1.

APIMaster

$ Details
-
Release Date
2026 May
Startup details
Country
Singapore
Employees
1 - 9

Rectangle features and specs

  • Ease of Use
    Rectangle offers an intuitive user interface that makes window management straightforward and user-friendly.
  • Customizable Shortcuts
    Users can easily configure keyboard shortcuts to better suit their workflow, making window management faster and more efficient.
  • Free
    Rectangle is available for free, making it accessible to anyone without the need for a financial investment.
  • Frequent Updates
    The app receives regular updates, introducing new features and ensuring compatibility with the latest macOS versions.
  • Lightweight
    Rectangle is a lightweight application that doesn't consume many system resources, ensuring smooth performance even on older Macs.

Possible disadvantages of Rectangle

  • Limited Advanced Features
    Rectangle lacks some of the more advanced features found in paid window management applications, such as multiple monitor support and more complex window arrangements.
  • MacOS Only
    Rectangle is only available for macOS, so users of other operating systems are unable to take advantage of its features.
  • Occasional Bugs
    Some users report occasional bugs or unpredictable behavior, which might require troubleshooting or waiting for a future update.
  • Learning Curve for Shortcuts
    While customizable shortcuts are a benefit, there is an initial learning curve for users to memorize and effectively use these shortcuts.
  • Basic Aesthetic
    The app's design and aesthetic are quite basic, lacking the polish and visual appeal found in some other similar tools.

APIMaster features and specs

  • Fingerprint Verification
    Trained on massive samples to identify the real model behind any API endpoint โ€” not by asking questions the proxy can fake, but by analyzing deep behavioral signals
  • API Key Tester
    Free tool to test OpenAI, Claude, Gemini & DeepSeek API keys โ€” verify connectivity and key validity instantly
  • Provider Leaderboard
    Real-time rankings by model authenticity โ€” see which providers pass or fail fingerprint checks
  • Smart Routing
    Auto-routes every request to the cheapest fingerprint-verified channel, with auto-failover across providers

Analysis of Rectangle

Overall verdict

  • Overall, Rectangle is highly regarded for its ease of use, extensive customization options, and the fact that it is free and open-source. It provides essential functionality without unnecessary complexity, making it suitable for both casual users and power users who need efficient window management.

Why this product is good

  • Rectangle is a popular window management tool for macOS, known for its simplicity and ease of use. It allows users to efficiently organize and resize application windows using customizable keyboard shortcuts or by dragging windows into pre-defined areas of the screen. This can enhance productivity by minimizing the time spent arranging windows and improving multitasking capabilities.

Recommended for

    Rectangle is recommended for macOS users looking for a straightforward, lightweight solution to manage application windows. It is particularly beneficial for those who frequently work with multiple applications at once, including developers, designers, and anyone who values a tidy and organized desktop environment.

Analysis of APIMaster

Overall verdict

  • APIMaster.ai appears to be a capable API management and development platform, but as with any tool, its suitability depends on your specific needs and workflow. Independent verification of its features and reliability is recommended before committing.

Why this product is good

  • Streamlines API design, testing, and documentation in a unified platform
  • May offer AI-assisted features to accelerate development and reduce manual effort
  • Potential to improve collaboration among development teams working on APIs
  • Could reduce time-to-market by automating repetitive API tasks

Recommended for

  • Developers and teams building or managing multiple APIs
  • Startups looking to speed up API development with AI assistance
  • Organizations needing centralized API documentation and testing
  • Backend engineers seeking to automate API workflows

Rectangle videos

SKYWALKER RECTANGLE TRAMPOLINE REVIEW!!!

More videos:

  • Review - Skywalker Rectangle Trampoline Review #1
  • Review - Marvin Malton 160 Rectangle Flying Hour Watch Review

APIMaster videos

No APIMaster videos yet. You could help us improve this page by suggesting one.

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Category Popularity

0-100% (relative to Rectangle and APIMaster)
Mac Tools
100 100%
0% 0
AI
0 0%
100% 100
Window Manager
100 100%
0% 0
Productivity
0 0%
100% 100

Questions & Answers

As answered by people managing Rectangle and APIMaster.

Which are the primary technologies used for building your product?

APIMaster's answer:

Next.js, Go, Python (Flask), PostgreSQL

What makes your product unique?

APIMaster's answer:

Fingerprint verification โ€” we test every provider weekly using behavioral fingerprinting to detect model substitution. You can see which providers serve real models vs fake substitutes on our public leaderboard. No other API marketplace does this.

Why should a person choose your product over its competitors?

APIMaster's answer:

APIMaster is the only marketplace that verifies what model you're actually getting. Competitors like OpenRouter route traffic without verification โ€” you might pay for Claude Opus but receive a cheaper model. APIMaster detects this and only recommends verified providers. Plus, prices are up to 90% off official rates โ€” you get both cost savings and model authenticity guaranteed.

How would you describe the primary audience of your product?

APIMaster's answer:

Developers who use OpenAI, Claude, or DeepSeek APIs and want to reduce costs without sacrificing model quality. Especially useful for developers in markets where direct API access is expensive or restricted.

What's the story behind your product?

APIMaster's answer:

Built after discovering that many cheap API resellers secretly substitute expensive models with cheaper ones. We built fingerprint detection first, then a marketplace that only lists providers that pass verification.

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare Rectangle and APIMaster

Rectangle Reviews

Best 6 Mac Window Managers
Rectangle shows that you donโ€™t need to dip into your bank account to get window resizer tools. This free Mac window manager lets you manage multiple windows using keyboard shortcuts, menu options, or by dragging and dropping. Just like Magnet, you can split your screen up into quarters, thirds, or halves.
Source: mackeeper.com
Top 6 Window Manager Apps for Mac
Most window manager apps for Mac support multiple monitors. They can help you move windows between screens and create custom layouts for each monitor. Many window manager apps โ€“ such as BetterSnapTool, Magnet, and Rectangle โ€“ offer this functionality.
The 6 Best Mac Window Management Tools
However, it might take some time for you to get used to the shortcuts in the Rectangle app since there are many. Furthermore, you can also add some of your apps to exceptions if you want to keep them away from Rectangle's shortcuts.

APIMaster Reviews

We have no reviews of APIMaster yet.
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Social recommendations and mentions

Based on our record, Rectangle seems to be more popular. It has been mentiond 479 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Rectangle mentions (479)

  • Ubuntu 26.04 LTS Released
    As a both old Linux and now decade user of MacOS, after I got used to no middle-click paste and no focus-follows-mouse: 1. Keyboard shortcuts are Emacs, Ctrl-A: start of line, E: end of line, K: kill selected or to end of line, Y to paste, etc. https://support.apple.com/en-au/102650#text 2. Karabiner elements (FOSS) fixes keyboard mappings outside of the Settings: https://karabiner-elements.pqrs.org/ 3. I have the... - Source: Hacker News / 4 months ago
  • Native Instant Space Switching on macOS
    Every macOS user uses Rectangle.app โ€” https://rectangleapp.com The ones who don't use it is because they donโ€™t know it exists. - Source: Hacker News / 4 months ago
  • Native Instant Space Switching on macOS
    I use https://rectangleapp.com/ and enjoy it. I have shortcuts to move windows to the left/right half of the screen, and cycle between monitors. This, combined with native cmd+tab and cmd+` is enough for me. - Source: Hacker News / 4 months ago
  • Make macOS consistently bad (unironically)
    Rectangle [1] is pretty much essential for me because of this. I use only a few keypresses (maximize window, move to one of the halves of the screen horizontally) but that is enough. My mouse very rately interacts with the borders of any window, or those buttons. I had to click on the green one that you mentioned in order to see what it did (yuck). [1] https://rectangleapp.com/. - Source: Hacker News / 5 months ago
  • Make macOS consistently bad (unironically)
    I use Rectangle [1] for window management. I only use three shortcuts: full screen, left half of the screen, and right half of the screen. My editors and chrome are always running in one of these modes. But for other apps like Messages, Notes, Music, etc - yeah I don't usually expand them to full screen. [1] https://rectangleapp.com/. - Source: Hacker News / 5 months ago
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APIMaster mentions (0)

We have not tracked any mentions of APIMaster yet. Tracking of APIMaster recommendations started around Jun 2026.

What are some alternatives?

When comparing Rectangle and APIMaster, you can also consider the following products

Magnet Window Manager - Magnet Developers

OpenRouter - A router for LLMs and other AI models

yabai - A tiling window manager for macOS based on binary space partitioning

BazaarLink - BazaarLink ๆ˜ฏๅฐ็ฃ AI API ่šๅˆๅนณๅฐ๏ผŒๆ•ดๅˆ GPT-4oใ€Claudeใ€Geminiใ€DeepSeek ็ญ‰ไธปๆตๆจกๅž‹๏ผŒๆไพ› OpenAI ็›ธๅฎน APIใ€ๅฐๅนฃ่จˆ่ฒปใ€ไธ‰่ฏๅผ็ตฑไธ€็™ผ็ฅจ๏ผŒๅ”ๅŠฉๅฐ็ฃ้–‹็™ผ่€…่ˆ‡ไผๆฅญไธฒๆŽฅๆœ€ๆ–ฐ AI ๆœๅ‹™ใ€‚

BTT Remote - A remote control for you Mac, using your iPhone or iPad

VoidLLM - Self-hosted LLM proxy with load balancing, multi-provider routing, API key management, and usage tracking. Privacy-first โ€” zero knowledge of your prompts.