20 Minute Timer
Ready at 20:00. Start now, then add a halfway, wrap-up, or final-minute cue only when it helps.
20-minute countdown
Starts when you press Start.
Ready for 20 minutes.
Start the full 20 minutes with one tap
The first screen opens at 20:00 with Start ready. There is no duration form to clear before a study block, writing sprint, room reset, meeting segment, or timed practice. The expected finish time appears when the countdown begins.
Choose a 10+10 or 15+5 checkpoint plan
Use the halfway cue when you want two equal ten-minute blocks. Use the five-minute cue when the last quarter of the session should be reserved for review, cleanup, questions, or a transition. The optional final-minute cue gives one last warning. Each selected checkpoint fires once per run.
Visual-only is the quiet default. Gentle and clear sounds require a user action because browsers restrict automatic audio. Test the selected alert first and keep the visible countdown as the fallback.
Finish-time and reload recovery
The countdown follows a saved target finish timestamp instead of assuming every browser callback represents exactly one second. When a background tab updates late, the display catches up to the current time rather than accumulating callback delay.
Reloading restores this page's running or paused state. If the deadline passed while the page was unavailable, the display changes to 00:00 and reports that the timer ended. The 20-minute timer uses its own local storage key, so it cannot overwrite the 5-, 10-, or 15-minute timers.
Browser timer limits
Fullscreen and Keep screen on can help during a shared activity, but browser and device support varies. A sleeping device, suspended browser, closed page, muted output, or battery restriction may stop an audible alert. Use the required dedicated timing system for medical, safety, legal, or operational deadlines.
Frequently asked questions
How do I start a 20-minute timer?
Press Start. The countdown is already set to 20:00, so no setup is required. Pause holds the remaining time, Reset returns to 20:00, and Restart begins a fresh twenty-minute run.
Can it alert me before the 20 minutes are over?
Yes. Enable the optional halfway, five-minute, or final-minute checkpoint. Each selected cue appears once per run, including when a delayed browser update crosses it.
What are the halfway and wrap-up checkpoints for?
The 10-minute cue divides the session into two equal blocks. The 5-minute cue marks a 15-and-5 plan, giving you a final section for review, cleanup, or transition. Choose only the checkpoints that match your task.
Does the timer stay accurate in a background tab?
The page calculates remaining time from a saved finish timestamp, which corrects ordinary background-tab throttling. A sleeping device, suspended browser, closed tab, or muted audio can still prevent an alert from playing at the exact moment.
Will my 20-minute countdown survive a reload?
A running or paused countdown is restored from this browser. If it finished while the page was away, the tool reports when it ended instead of silently starting another twenty minutes. Reset clears the saved run.
Is this a Pomodoro or 20-20-20 reminder?
No. This page runs one fixed 20-minute countdown. It does not automatically start a break, repeat on a schedule, or provide a health reminder. Restart it manually only when that fits your own routine.