A lightning talk is a short, single-topic talk capped at five minutes — long enough to make one clear point, short enough to keep a packed agenda of speakers moving. This timer counts those five minutes down on a big display and beeps once when you are out, so you can pace yourself without a moderator waving you off.
You drive your own slides for a lightning talk, so all you need to know is that you are inside the limit. Some events run three-minute lightning talks instead — open the preset in the editor and reset the countdown to whatever your slot allows, then rehearse against it until your point lands with time to spare.
Twenty slides, twenty seconds each — 6:40 of talking to whatever is on screen, with a beep at every change. Set your deck to auto-advance at 20 seconds and let the timer keep you honest.
A flat five minutes — twenty slides, fifteen seconds apiece, five seconds tighter than Pecha Kucha and far less forgiving. The beep is your cue to click on; set your slides to advance to match it.
Sixty seconds to say who you are and why it matters before the doors open. Drill it until the ending lands without a rush; trim it to 30 seconds in the editor for the sharper cut.
Eighteen minutes — the TED ceiling, the point past which a talk loses the room. It is a limit, not a target, so rehearse until yours finishes comfortably under. Reset the length in the editor for any other cap.