There are a multitude of add-ons for Firefox and Chrome. So many in fact that it’s easy to waste hours trying some of them out. To save you time, these are 5 of the best for webmasters – in my opinion.

Please ensure you are in Firefox or Chrome before clicking any of the relevant links below.

Testing browser compatibility

It’s important to test how your website looks in different browsers, these add-ons simplify testing for you by enabling you to open a page in a range of browsers.

Open With is a must have add-on for Firefox, ideal for testing your new site content in a range of browsers, including Internet Explorer, Chrome and Safari. In Chrome there are seperate extensions that will let you view your page as it would appear in Internet Explorer (IE Tab) and Firefox (Chrome Firefox Tab).

Get the Open With Firefox Add-On

Get the IE Tab Extension for Chrome

Get the Chrome Firefox Tab Extension for Chrome.

Inspecting website code

Firebug is an essential tool for advanced webmasters. Once installed this add-on puts a wealth of development tools at your fingertips while you browse. You can edit, debug, or monitor CSS, HTML, and JavaScript live in any web page. Right click on any web page and choose “inspect element” to get started. If you use Google Chrome, a similar tool is built in – simply right click and choose “inspect element”.

Get the Firebug Firefox Add-On

Colour pickers

Colour pickers are useful tools that allow you to see exactly what colour is used on a website, it’s really useful if you need to know an exact colour (from a logo for example) when coding.  ColorZilla is an advanced eyedropper, colour picker and palette viewer for Firefox. Color Pick is a simple colour picker eye dropper for Google Chrome that allows you to find out the colours used on any web page.

Get the ColorZilla Firefox Add-On

Get the Color Pick Chrome Extension

HTML validation

Making sure your web pages are using valid HTML code is vital, the HTML Validator add-on will display the number of errors in a HTML page in the form of an icon in the status bar when browsing in Firefox or Chrome.

Get the HTML Validator Add-On for Firefox

Get the HTML Validator Extension for Chrome

Measuring Tools

If you need to know the size of an image or space on your website, MeasureIt is a simple add-on allowing you to draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.

Get the MeasureIt Add-On for Firefox

Get the MeasureIt Extension for Chrome

3 more essential extensions for Google Chrome

If you are a Chrome user but miss some of the features of the more bloated browsers, extensions can add functionality back in. Try out the following extensions.

RSS Subscription Extension (by Google) – adds one-click RSS feed subscription to your toolbar.

Email this page (by Google) – this extension adds an email button to the toolbar which allows you to email the page link using your default mail client or Gmail.

Downloads – access the Downloads window directly from the toolbar.