Web app · Health And Fitness
Roundbell
The interval timer you can read from across the room — now in any browser
Tabata, EMOM, boxing rounds and your own circuits with a full-screen colour-per-interval player, bell and 3-2-1 beeps, voice cues, and a history that tracks your streak and weekly minutes. Free, no install.
Stored in your browser only. Nothing you do in the web version is sent to our servers. Clear your browser data and it's gone — so export a backup from the in-app menu if you want to keep it.
In your browser
What you can do in Roundbell on the web
Quick start in three taps
Set work, rest and rounds with steppers and hit Start — no setup screen, no account.
8 presets + unlimited custom timers
Tabata, HIIT 40/20, EMOM, boxing rounds, circuit, AMRAP, run/walk and stretch, or build your own with named, coloured intervals, round rest, get-ready and cool-down.
Full-screen player
The whole screen changes colour per interval with a huge countdown, next-up, round counter, progress bar, skip and back.
Bell, beeps and voice
A bell on every change, 3-2-1 beeps, spoken interval names and an optional halfway cue — all generated in your browser.
History, streak and weekly minutes
Every finished (or stopped) workout is logged with a bar chart of minutes per week and a 12-week heatmap.
Stays in your browser
Timers and history are saved locally; export a JSON backup any time.
Screens
Every screen, rebuilt for the browser
-
1
Timers
Streak and weekly minutes, quick start, and all your presets and custom timers.
-
2
Timer detail
Sequence preview, intervals, rounds and recent runs of one timer.
-
3
Timer editor
Name, emoji, coloured intervals, rounds, round rest, get-ready and cool-down.
-
4
Player
Full-screen colour-per-interval countdown with cues and controls.
-
5
Summary
Duration, rounds completed, streak and weekly totals after a workout.
-
6
History
Minutes per week, 12-week heatmap and every logged workout.
-
7
Settings
Cues, get-ready length, backup, sample data and erase.
Try it with sample data: Loads the 8 presets, a custom kettlebell ladder and nine logged workouts across the last two weeks. You can start fresh at any time.
Ready? It's free.
Sign in once and every All Things AI web app opens instantly. No install, no subscription, no data leaving your browser.
Your say
Is Roundbell useful? Tell us what to build next.
Sign in to vote.
Tell us what to build next.
Sign in to leave a comment or vote — it takes a few seconds.
Sign in to commentNo comments yet — be the first to say what this app should do next.
Questions
Is the web version of Roundbell free?+
Yes. Sign in with a free All Things AI account and use every screen — no subscription, no in-app purchases.
Where is my data stored?+
Only in this browser's local storage. Nothing you enter is sent to our servers, so we can't see it, back it up, or restore it. Clearing site data, a private window, or another device starts empty. Export a backup from the in-app menu to keep it.
Do I need an account?+
You can read about the app without one, but you must sign in to open it. Sign-in is free and takes a few seconds with Google.
How is the web version different from the Roundbell iPhone app?+
Timers keep running while the tab is visible; if you switch tabs the countdown continues but audio cues may be delayed by your browser. The iPhone app adds background audio, haptics and daily reminders.