Run two versions of Firefox on Mac OSX

Yesterday Firefox 4.0 was released and web developers everywhere celebrated a really great browser.  The browser comes packed with a super fast JavaScript engine called JägerMonkey. Now don't get too excited just yet! We still need to keep that old version of Firefox around for testing; we can't assume everyone has upgraded to Firefox 4. So, to run both Firefox 3.6 and Firefox 4.0 on the same machine, just follow these simple steps:

* Open up your Applications folder and find your old version of Firefox

* Right click-> get info.

* Rename to "Firefox36.app"

* Download Firefox 4.0 and install as normal

* Celebrate that you now have 1 more browser to test in!

Really simple! If someone knows how to do this on the Windows and Linux side, I would love to hear how.

Find an issue with this post? Think you could clarify, update or add something?

All my posts are available to edit on Github. Any fix, little or small, is appreciated!

Edit on Github

Syntax Podcast

Hold on — I'm grabbin' the last one.

Listen Now →
Syntax Podcast

@wesbos Instant Grams

Master Gatsby

Master Gatsby

Building modern websites is tough. Preloading, routing, compression, critical CSS, caching, scaling and bundlers all make for blazing fast websites, but extra development and tooling get in the way.

Gatsby is a React.js framework that does it all for you. This course will teach you how to build your websites and let Gatsby take care of all the Hard Stuff™.

MasterGatsby.com
I post videos on and code on

Wes Bos © 1999 — 2021