I strongly recommend everyone start using strict mode now. There are enough browsers supporting it that strict mode will legitimately help save you from errors you didn’t even know where in your code. Make sure you don’t include the pragma globally, but use IIFEs as frequently as you like to apply strict mode to as much code as possible. Initially, there will be errors you’ve never encountered before – this is normal. Make sure you do a fair amount of testing after switching to strict mode to make sure you’ve caught everything.