PerfectPixel is a Chrome extension developed by WellDoneCode LLC. It is a useful tool for web developers and markup designers as it helps them achieve pixel perfect accuracy in their website development.

With PerfectPixel, developers can overlay a semi-transparent image over their developed HTML and compare it pixel by pixel. This allows them to easily identify any discrepancies and make necessary adjustments.

The extension offers several features to enhance the user experience. It supports multiple layers, allowing users to work on different aspects of their website simultaneously. Users can also invert and scale layers for better visibility. Each website can have its own separate layers, and these layers are saved between browsing sessions.

PerfectPixel has a minimalistic and easy-to-use UI. It supports drag-and-drop file upload, pasting from URLs, and pasting from the clipboard. Users can navigate through the overlay image using keyboard arrow keys and mousewheel.

In addition to the free version, PerfectPixel also offers a PRO version. The PRO version removes ads, adds layer rotation, allows appearance customization, and provides premium support.

Overall, PerfectPixel is a valuable tool for web developers and markup designers who strive for pixel perfect accuracy in their work. It provides essential features and a user-friendly interface to facilitate the development process.

Please note that the extension is ad-supported, but the ads are only injected into the extension panel and not into websites.