There are 2 free online timers created specifically to time your Rubik's cube solves.  The Rubik's cube timers are build to support the official timing rules of a Speedcubing competition run by the World Cube Association (WCA).

The rules are:

  • You have 15 seconds or less to inspect the cube before starting the timer.
  • You average of 5 time determines your rank for a round in the competition. This average is calculated as follow: The best and worst time is removed and the average of the middle three times become your official average.  

Rubik's cube timers at the minimum:

  • Provide Computer generated scrambles for diferent types of puxzzles
  • Countdown the inspection time
  • Saves each time
  • Calculates your averages

Best Rubik's Cube Timers:

cstimer

Cstimer.net 

This is a highly customisable timer with the option to connect external timers via Auxiliary cables or  Bluetooth. It also has the option to show the scramble visually so that you can verify that you scrambled correctly. 

 

  • Provides computer generated scrambles for many puzzles.
  • Saves times and averages
  • Group times in "Sessions"

CubeTime

CubeTime (iOS)

https://apps.apple.com/dk/app/cubetime/id1600392245 

This is iOS app timer with a clean interface.  

 

  • Provides computer generated scrambles for many puzzles.
  • Saves times and avarages
  • Group times in "Sessions"
  • Provides helpful statistics