Pixel Perfect Pro

Pixel Perfect Pro is a browser extension for designers and developers who want a webpage implementation to match a design mockup down to the last pixel. It focuses on live visual comparison between a design file and a page in the browser, with the stated aim of achieving pixel-perfect accuracy.

Its feature set centers on overlaying design images on top of a webpage and adjusting that overlay while working. The extension offers side-by-side and onion skin comparison modes, opacity and grid controls, unlimited layers, horizontal and vertical alignment tools, inversion and scaling, keyboard-arrow and mouse-wheel adjustments, an integrated ruler, drag-and-drop upload, support for large images up to 50 MB, and iframe overlay support for embedded content and complex page structures. The workflow described on the site uses PNG, JPG, or WEBP files, which can be uploaded, positioned, and then fine-tuned against the implementation.

Pixel Perfect Pro is available as a browser extension for Chrome and Firefox, and the page also names Edge and other Chromium-based browsers as supported. It is described as free, with optional donations via Buy Me a Coffee, and all features are said to be available at no cost. The extension is described as 100% local and private, and as occupying minimal space in development panels. The site also says it works with localhost and local development servers. It is presented as a tool for designers and developers, and the page includes a 4.5 rating on the Chrome Web Store and a claim of 15,000+ active users.