President of WebFX. Bill has over 25 years of experience in the Internet marketing industry specializing in SEO, UX, information architecture, marketing automation and more. William's background in scientific computing and education from Shippensburg and MIT provided the foundation for MarketingCloudFX and other key research and development projects at WebFX.

Firebug is a revolutionary Firefox extension that helps web developers and designers test and inspect front-end code. It provides us with many useful features such as a console panel for logging information, a DOM inspector, detailed information about page elements, and much more.

Though Firebug is already fully packed with features out of the box, several extensions out there can enhance its utility. In this article, you will find the 10 best Firefox extensions for Firebug that will make your life, as a developer or designer, easier.

1. Pixel Perfect

Pixel Perfect allows you to overlay web layouts and other design compositions onto a web page so that you can accurately (and easily) write your CSS and HTML. By being able to toggle a web composition on or off, web developers and designers can have a visual guide for pixel-perfect accuracy of the position and dimensions of web page components. Check out the video demonstration to Pixel Perfect in action.

Install Pixel Perfect

Page Speed is an open source Firebug add-on for evaluating web page performance, giving developers suggestions on front-end performance optimizations they can carry out. Tests and evaluations are based on Google’s Web Performance Best Practices developed through Steve Sounder’s work. Make sure to read the Page Speed user guide for complete documentation of its many features.

3. CodeBurner

CodeBurner, released by SitePoint, extends Firebug to provide a built-in HTML and CSS reference. The extension also presents contextual information based on what is currently in Firebug’s CSS and HTML panels. The references are very helpful, showing you information about browser compatibility and W3C Recommendation compliance of page elements, among many other types of information.

Install CodeBurner

FireRainbow is a simple Firebug extension that fills in a sorely desired function: code syntax highlighting. FireRainbow colorizes JavaScript, CSS, and HTML for improved readability of code being reviewed or inspected in Firebug. There are currently over 20 different FireRainbow themes that you can choose from, giving you some options for customization.

Install FireRainbow

Inline Code Finder is great for hunting down inline JavaScript and CSS and is perfect for developers refactoring existing markup to separate structure (HTML) from style (CSS) and function (JavaScript). The usage of the tool is simple: it searches the entire web page for inline code and provides the developer with contextual information about the inline code it finds. The newest version gives you the ability to filter certain groups of inline code.

Install Inline Code Finder

Developing web applications that utilize cookies can be time-consuming. Firecookie, a Firebug extension, gives you a host of options and features strictly for working with cookies. The extension allows you to view, inspect, export, and manage cookies, log cookie events (creation, deletion, etc.), and much more. The latest version of Firecookie adds several improvements such as the ability to list only cookies sourcing from a subdomain.

FirebugCodeCoverage is a benchmarking Firebug extension inspired by Selenium IDE for determining the percentage of your code being executed for time duration, known as code coverage. This is typically measured during automated testing to see how well the test cases are able to thoroughly test your code (with higher percentages being your goal).

8. SenSEO

SenSEO is a Firebug extension that analyzes a web page and indicates how well it is doing for single-page whitehat search engine optimization. The extension checks for correct use of meta tags, presence of a title, headings, and other relevant criterions for optimal search engine optimization.

Install SenSEO

YSlow evaluates a web page for performance and suggests potential places for improvements. YSlow is based on YDN’s Best Practices for Speeding Up Your Web Site and gives you letter grades on one of the three predefined (or user-defined) rule sets. It has a handful of useful features such as displaying information and statistics about web page components, and integration of optimization tools such as JSLint and Smush.it.

Install YSlow

Firefinder is for quickly finding web page elements that match CSS or Xpath selectors that you input as your search criteria. Firefinder is great for testing which page elements are affected by a CSS style rule as well as for highlighting and finding elements that match your searches.

Install Firefinder

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