Bursta is a free interval timer for rounds. Boxing, muay thai, MMA and wrestling, HIIT and Tabata, EMOM and an AMRAP clock, rest between sets, planks, stretching, and paced, box and 4-7-8 breathing. There is no account to make and nothing to install: it opens in the browser you already have, on a phone in a gym bag, a laptop on a bench, or a television on the wall of a studio.
Every reading comes off the wall clock
A timer can keep a counter and add to it on every tick. When a browser throttles a background tab, or a phone drops a frame, or one render takes longer than a frame is allowed, the additions that never happened are gone for good and the bell arrives late. Over a long session the lost time adds up, and a counter has no way of knowing it is behind.
This one keeps no counter. It writes down the moment a workout began, and every frame it subtracts that from the time of day. There is nothing that can fall behind. A stalled thread can hold the digits on the screen still for a second, and the interval those digits describe is unchanged when it catches up.
Our tests run forty-five minutes on a simulated clock, read more than ten thousand times at uneven steps, and wake a tab after six minutes suspended. The count matches the wall clock at every reading. Sound is the weak point: a browser may pause the audio of a hidden tab, so keep the timer in front.
You read the colour before you read the clock
A round timer is looked at from across a room, mid-set, through sweat. So a phase is not a badge in a corner here. It is the whole surface: the ground, the light on it and the contact under the dial all change together, and the number is the last thing you need rather than the first.
Press start above and the page does this for real. Ten seconds of verdigris to get your hands up, then the ember of a round, then the olive of a corner, and back again until the workout is done.
Get ready
0:10
Ten seconds before the first bell, so your hands are up before anything asks for them.
Work
3:00
A professional round is three minutes under the ABC Unified Rules, and Nevada’s statute allows no longer.
Rest
1:00
One minute in the corner, the rest the ABC rules and the Nevada statute both set.
The formats
Every timer here says where its numbers came from
Each timer page keeps the numbers a rulebook or a study fixed apart from the ones we chose. On the boxing page the three-minute round comes from the ABC Unified Rules and twelve rounds is the most Nevada’s statute allows. Opening on all twelve is our choice, and the page says so. Open one from the list at the top and it is already loaded and ready to start.
Change every number, then press start
Rounds, work, rest and the get-ready count are editable on any of those pages, and a session can be cut into sets with a break between them. Nothing is held back for a paid tier, because there is no paid tier and no third workout that asks you to pay for it.
What you set is kept in your own browser, and a link carries it to whoever you send it to. Keyboard runs the whole thing: Enter starts and pauses, the arrows step an interval either way, F asks for the screen.
Six palettes, and a phase keeps its meaning in all of them
The same four grounds are drawn six ways. They are not decoration: each one is solved so that get ready, work, rest and done stay apart from each other, and so that the ink on them stays readable at the distance the clock is read from. Cinder is what a first visit opens in. Press one below to try it here: the timer at the top of this page repaints, and every timer page opens in it after that.
The phone app is not published yet
Bursta was an Android app before it was a website. That app is built and running, but it has not been published yet, and an iPhone version comes later. So there is nothing on this page to download, no store badge and no button pretending there is one.
When it does land it will do the things a browser cannot: cues that keep coming with the screen locked and the phone in a bag, a lock-screen card showing the round you are in, and a calendar that asks you for the session. Until then this page is the whole product, and it needs no account.