Pixel Perfect

Overlay web designs on HTML for pixel-perfect development in Firefox.

Free

Description

Pixel Perfect is a Firefox browser extension designed to assist web developers and designers in achieving pixel-perfect accuracy between a web composition mockup and the developed HTML. It allows users to easily overlay a semi-transparent image of the design composition on top of the live web page.

By toggling the composition overlay on and off, developers can visually identify discrepancies down to the pixel level. The extension features an opacity slider, enabling users to see both the design overlay and the underlying HTML structure simultaneously. This functionality integrates smoothly with developer tools like Firebug, allowing for real-time inspection and adjustments. While acknowledging minor rendering differences across browsers and operating systems, Pixel Perfect serves as a valuable tool for maintaining the integrity of detailed web designs during the development process.

Key Features

Web Composition Overlay: Layer design images directly onto HTML pages.
Toggle Visibility: Easily switch the overlay on and off for direct comparison.
Opacity Control: Adjust overlay transparency to view the underlying HTML structure.
Developer Tool Compatibility: Designed to work alongside tools like Firebug.
Pixel Difference Inspection: Visually identify discrepancies between the design and the coded page.
Keyboard Controls: Use arrow keys for fine, one-pixel adjustments of the overlay position.

Use Cases

Comparing design mockups precisely to developed HTML.
Ensuring front-end development accurately matches design specifications.
Debugging CSS layout, alignment, and positioning issues.
Maintaining design fidelity throughout the web development lifecycle.
Performing visual quality assurance on web pages.

Frequently Asked Questions

I upload the overlay and clicked the toggle box, but nothing appears. Why?

This can happen if the overlay div ('pp_overlay') has its height and width properties set to '0px'. You can use Firebug to inspect the 'pp_overlay' div (usually near the closing body tag) and manually change the height and width to the correct values as a temporary workaround.

Why is the Pixel Perfect panel duplicated?

Currently, Pixel Perfect does not support multiple browser tabs. Using the extension in more than one tab simultaneously will cause the panel layout to be loaded again, duplicating it.

The position controls are not responsive when clicking rapidly. What can I do?

This is a known issue being worked on. As an alternative for precise adjustments, you can use the arrow keys on your keyboard to move the overlay one pixel at a time.

What if I have an issue that is not listed here?

Please check the issue tracker at https://code.google.com/archive/p/pixelperfectplugin/ first to see if your issue has already been reported. If not, feel free to create a new issue there.