Hello,

Based on the information provided with your help request, it appears you are up-to-date already. Following the instructions here Update Firefox to the latest release will ensure you have the latest version of Firefox for your system.

Please let us know if this helps!

Only download an install Firefox from the official Mozilla servers and ignore a pop-up on website that you need to update or install a newer Firefox version. Such messages are usually scam to seduce you to install malware.

See Help > About

Where did you see 33 at as Firefox will not be at version 33.0 for Release or even in development for quite a while still still.