Start the clock, hold your plank, and get a cue every 30 seconds. Every hold is saved so you can watch your personal best climb over time.
No holds logged yet. Start the timer and stop it to save your first one.
A plank looks static, but the time you can hold good form for is one of the simplest, most repeatable measures of core endurance you have.
Cues at 30, 60, 90 and 120 seconds give you something to aim for mid-hold without watching a clock.
Only completed holds count toward your record, so it always reflects a real, saved attempt.
Every session is timestamped in your history, so you can see improvement week over week.
The plank is an isometric exercise, meaning the muscles contract without changing length or moving a joint through a range of motion, which is exactly why a simple timer is the right tool for measuring it — there's no rep to count, only time under tension. Core endurance measured this way correlates with better spinal stability and posture, and tracking it over weeks is more informative than a single number, since form quality matters as much as duration. That's the reasoning behind the milestone cues at 30, 60, 90 and 120 seconds: they're spaced closely enough at the start to encourage beginners past the hardest early seconds, and they keep firing for more advanced holds without needing to redesign the tool. Stopping the timer the instant your hips sag or your form breaks, rather than trying to squeeze out a few more seconds of a bad plank, keeps your logged personal best meaningful as a measure of good-form endurance rather than just raw stubbornness. History and personal best are stored with localStorage, so they persist between visits on the same device and browser without any account or sign-in, and nothing about your workout ever leaves your browser.
Isometric holds are measured in seconds, not reps, which is exactly what this timer tracks.
Milestones encourage you to keep pushing, but stopping at the first form break keeps your best honest.
History and personal best live in your browser only — no account needed.
Select Start hold and the clock counts up in real time from the moment you press it. Select Stop & save the instant you drop out of the plank to record the exact duration.
Your hold duration is added to the session history with the current date and time, and if it beats your existing personal best, the personal best display updates immediately.
While you're holding, the timer shows a toast message and plays a short Web Audio beep the moment you cross 30, 60, 90 and 120 seconds, so you get encouragement without checking the screen.
Yes. Every completed hold is saved to your browser's local storage, so your history and personal best are still there the next time you open the tool.
Yes. Uncheck Milestone sound cues in the panel to keep the toast messages silent while still tracking your time and history.
More free browser-based tools for training and recovery from My Panda Toolbox.