In Firefox, you click on the gear icon in the top right of the console, then check "Show Timestamps". Though you probably want the per-tab Console there (ctrl-

In Firefox, you click on the gear icon in the top right of the console, then check "Show Timestamps". Though you probably want the per-tab Console there (ctrl-shift-k). ctrl-shift-j would give you the multiprocess browser console, which is very noisy.