radialtimers.com
Thirty seconds of work, ten of rest, eight rounds, advancing on their own. The dial empties fast enough to read mid-exercise, and the chime at each change means you never watch for the switch.
High-intensity interval training means short efforts near your limit with rests too short to fully recover, repeated. The 30/10 split is a workhorse: thirty seconds is long enough to demand real output on a bike, a rower, burpees or hill sprints, and ten seconds is only enough to shake out and reset. On this page eight rounds run on their own with a chime at every change, and the cycle finishes on the eighth work block, so the whole thing takes 5 minutes 10 seconds. During work the dial sheds a ring every 1.5 seconds, which reads from the floor mid-burpee.
Put the screen where you can see it from the floor and fullscreen the dial; the rings are bigger than any digit and you will be watching from an awkward angle. Turn the volume up because the chime is your cue to stop, not the dial. If you train with someone on the other side of the room, a Room puts the same countdown on both phones.
Going out too hard in round one and coasting rounds five to eight is the classic error; the first two rounds should feel controlled. Skipping the warm-up on a five minute workout is tempting because it doubles the time, and it is still the wrong call. Using ten seconds of rest to look at the phone is another: the rest is for breathing. And doing this every day is not a plan. Two or three sessions a week with easy days between is what interval training is built on.
For the shortest sharp version, the Tabata 20/10 is four minutes and harder than it sounds. For stations where you need to set up between efforts, 45/15 or the 40/20 workout leaves room. Longer work with longer rests, say 60/30, can be built in Cycles in a few seconds. The guide on interval and HIIT timing compares them.
Every change: work to rest, rest back to work, and the end of the last round.
A common interval split: long enough to load the effort, short enough to keep intensity high. For steadier efforts, pick a plain duration below.
Add it as a browser source in OBS; the background stays transparent. Change t for any length.
A radial timer is a free online countdown timer you set in one click: pick a length, press Start, and an alarm sounds at zero. Run several timers at once, take one fullscreen, or pop one out picture-in-picture to float over other apps. Every timer keeps counting in a background tab, and any timer exports as a video. No download, no sign-up.
Its dial draws the countdown as 20 concentric rings, one for each twentieth of the duration. Rings empty one by one, outermost first, so a glance shows how far along you are without reading a digit.
Yes. The countdown follows the clock, so it stays on time while you work in another tab and still chimes at zero. The picture-in-picture popout keeps a small dial in view the whole way.
Yes. Any timer exports as an MP4 or a transparent WebM of the whole countdown, up to 4K and 60 fps, in 16:9, vertical, or square.
Yes. In OBS, add a browser source pointing at radialtimers.com/overlay?t=25m and a transparent dial counts down over your scene. Change t for any length, like 90s or 3h.
As many as you need. Each timer gets its own dial and runs on its own, which suits interval workouts, several dishes on the stove, or a room of activity stations.