The 5 Best Firefox Extensions for a Web Developer

Since the Firefox browser was born, disputes over which of the browsers is better have not subsided on the Internet. Judging by the site statistics now 80% will prove that Inernet Explorer is the best, 13% – that there is nothing better than Firefox, well, the remaining 7% will praise Opera, Safari and other creations for “comfortable spending time on the Internet.”

And only among web developers – complete silence! Because they know that the best browser is Firefox.

And they will be right, because no one has ever created such an excellent tool for their work and leisure.

And the reason for this is not so much in the browser itself, but in its extensions (Add-ons). Ask any familiar web developer if he knows what Firebug or WebDeveloper is, and be sure that he will answer in the affirmative, because without these excellent tools it is difficult to imagine the modern process of developing web products.

This concludes with an introduction and I turn to the actual topic of today’s review, which flaunts in the title. And I’ll start with Firebug.


Now you rarely meet a network user (if his experience is at least > 1 week) who would not have heard about the advent of the Web 2.0 era on the world wide web. Like mushrooms after the rain, various Digg-and, , YouTube and other “social” creations.

And I am sure that Firebug played an important role in the speed of this “offensive”. Because only he was able to provide developers with a convenient environment for working with JavaScript (+Ajax), CSS, DOM.

The functionality of Firebug is really impressive:

– HTML analysis and editing;

– working with CSS (editing, visualization, etc.);

– network traffic analysis;

– debugging JavaScript;

– working with DOM.

And all this in a very convenient form! No DOM inspectors were even standing around.


A real Swiss knife of a web developer. If you want to know everything about a certain web page, then WebDeveloper (Fig. 1) will allow you to do it easily and simply.

That’s what he can do:

– working with cookies (viewing, changing and deleting);

– working with CSS styles (again – viewing, changing, and debugging style sheets for printers, PDAs, etc.);

– various hacks with forms (viewing elements, changing the data transfer method, changing the maximum length, etc.);

– working with page images (disabling, displaying sizes and properties, etc.);

– usability analysis;

– emulation of different monitor resolutions…

In general, just a complete enumeration of all the points of this toolbar will take up the volume of this entire article.

HTML Validator

If you want to create valid HTML markup (I really hope that this is what you want to create), then HTML Validator will simplify this process simply to the point of outrage. It will not only show you where you made a mistake, but also explain how to fix this error. Look at the screenshot (Fig. 2) and you will understand everything for yourself.

Live HTTP Headers

Everything is clear from the name. Allows you to view HTTP headers sent and received from the server. As a developer for the Apache server, this plugin is especially close to me. More than once he helped me out in search of bugs in the work of modules or errors in the Apache configuration.

Separately, it is worth noting its capabilities in sending GET and POST requests. Not Curl, of course, but still convenient.

User Agent Switcher

Well, the last in today’s list is the User Agent Switcher. Everything is strict here, but with taste. Allows you to change the User-Agent of your browser with two mouse clicks. They wanted to – and became an Opera or Nokia6630, but at least a Philips kettle! As you have already understood, this addon allows you to test interfaces for various HTTP clients.