May 20th 2015

Using multiple Firefox profiles on OS X

If you’re developing Firefox extensions, it may be useful to have multiple profiles: one for every day use containing the extensions/setting you use regularly, and another as a development environment. Separate profiles ensure that if you accidentally break something during development, your usual browser environment will remain the same. I’ve found this to be particularly useful so thought I’d write a post about it. Before I get started, I should point out this post is geared towards OS X users.

First of all, you will need to access Firefox’s profile manager tool. To do this, type the following into the Terminal-

/Applications/ --profilemanager

This will cause the Profile Manager window to appear. If you’re already a Firefox user, your default profile should appear. Click on the Create Profile button to make a new profile. Give it a name (remember this name) and choose the folder in which you wish to store your profile information. For the purpose of this post we’ll call our profile “devProfile”. That’s all there is to creating a new profile however, if you wish to use it as a development environment, you must launch it with Firefox. The next part of this tutorial will show you how to create a second instance of Firefox for your development profile.

Open the Script Editor app. On Yosemite, this can be found in Applications > Utilities > Script Editor. Type in the following-

do shell script "/Applications/ -P devProfile"

When typing in the script, watch the quote- ensure they are regular double quotes, rather than smart quotes. Save the file as an Application. Now we need to Info.plist file. This can be found by right-clicking on the Application you just saved > Show Package Contents > Contents. Find these 2 lines-


Under the true tag, add the following 2 lines-


LSUIElement is a Launch Key in OS X. Launch keys help to launch apps and figure out which apps should open certain document types. According to Apple’s Documentation, LSUIElement Specifies whether the app is an agent app, that is, an app that should not appear in the Dock or Force Quit window.

That’s really all there is to it. You can change the icon on the new Launcher Application you have just created (or leave it as the default script icon, but that’s a bit boring). When clicked, the Application will cause another Firefox icon to appear in the Dock. This instance of Firefox will launch with the development profile you created.

Of course, an alternative way of launching a new instance of Firefox with a development profile is to use the Automator app.

March 13th 2010

Firefox 3.6

Has anyone else out there downloaded Firefox 3.6 yet? I must say, I’m impressed with the new Persona feature that it includes.

Remember Firefox Themes? If you wanted to install one of them, you first had to locate one which you thought might look ok. Yes, you could see a preview of the theme provided by the author but that wasn’t a guarentee of how it would look on your system. From there, you had to download and install the theme before restarting Firefox (the old theme remained in place until the browser restarted). Much of the time, on restarting Firefox, you would discover that the theme you had chosen looked awful and you ended up wanting to revert to what you originally had. Again, you can to choose the original theme before restarting Firefox once more in order to see the change.

All in all, themes were a bit of a pain in the backside, wouldn’t you agree?

The Persona feature included in Firefox 3.6 is similar to the old themes feature. It basically allows you to apply a skin to your browser with one click, customising it instantly. Unsure if the theme will look good on your system? 1 click and you can preview it fully in the browser. Like what you see? 1 click and its installed and ready to use. Personas certainly make things much easier in comparison to themes.

If you want to see the Persona gallery and get started, check out the Firefox website.

Here’s a rather rubbish screenshot of my system at the moment (and yes, I know this is a rather girly theme)-

FF screenshot

Persona Screenshot

July 3rd 2009

Spellcheck your site

Here’s a tip for you web designers out there.

Ever needed to spellcheck your website once it’s live online?  I’ve just found out that it’s possible to do this in Firefox.  Go to the website you want to spellchecked and then enter the following in the address bar-

javascript:document.body.contentEditable=‘true’; document.designMode=‘on’; void 0

This tip came courtesy of Urbanos Blog

javascript:document.body.contentEditable='true'; document.designMode='on'; void 0
October 19th 2008

Useful Firefox add-ons

How many of you use Firefox? Come on, raise your hands.

A few days ago I was looking though the add-on area of the mozilla site and came across a few neat tools so, I thought I’d share some of the Firefox add-ons I use.

Adblock Plus, used in conjunction with Filterset.G.Updater
What can I say? I completely adore this add-on. It gets rid of 99.9% of ads and banners. For that, I love it.

Colourful tabs
Ok, it’s not the most useful Firefox add-on in existance but it makes each tab you open a different colour, resulting in a very pretty interface.

This small add-on makes it even easier to navigate between the various tabs you may have open at a given time. It provides a similar feature to the Alt+Tab shortcut in Windows.

Down Them All!!
Allows you to download multiple items from a page at the same time. Tired of right-clicking and “saving as”? Well, down them all is for you!

Extremely useful for when one is web designing. It allows you to inspect, edit and monitor CSS, HTML and JavaScript.

Foxy Tunes
This neat little add-on allows you to control media players without leaving your browser. Handy if you’re like me and always have music on!

IE Tab
This allows you to view a page in Firefox, using IE rendering. Pretty cool!

Again, this isn’t really all that useful but it does provide you with a splash screen while Firefox is loading. It’s something to look at I guess.

Web Developer
One of my favourite add-ons. What does it do? It adds a menu and a toolbar containing a plethora of web developer tools. Get it. Get it now!