Online Stopwatch

What each button does

The stopwatch has two controls under the digits. The large button on the right reads Start, then Pause while the clock runs, then Resume once you have paused. The round arrow on the left is Reset. A small status label above the digits reads Ready, Running, or Paused.

• Start

  begins at 00:00.00. The first time you press it, your browser may ask for permission to show notifications, and a short chime plays if the sound is on.

• Pause

  freezes the clock where it is. Resume carries on from the same reading.

• Reset

  sends the clock back to 00:00.00 straight away, with no "are you sure" box. It also ends the run, which is the moment a signed-in run is saved.

Reset clears the digits, so read the number before you press it. The stopwatch has no button that marks a time while the clock runs, so if you want to remember a reading, write it down as you go.

Reading the display

The digits show minutes, seconds, and hundredths of a second, like 02:07.44. The two digits after the dot are hundredths, so 44 is a little under half a second. The number refreshes about 100 times a second, but it shows only hundredths. It does not show thousandths, so it is not a true millisecond stopwatch. Once the run passes one hour, two hour digits appear on the left, as in 01:12:30.05.

While the clock runs, the browser tab also shows the minutes and seconds, so you can check it from another tab. After an hour the minutes keep counting in the tab, so 75 minutes reads 75:00. A pause symbol appears in front when the stopwatch is paused. On a phone, the digits shrink to fit a screen as narrow as 375 pixels.

Hundredths are worth having when what you time is short. Timing one multiple-choice question shows whether you spend 20 seconds or 50. Timing how long you take to write out a formula from memory tells you whether that fact is solid or still slow. For a long sitting they are noise. If you read for an hour, 58:12.66 tells you no more than 58 minutes.

What gets saved when you sign in

What happens behind the digits depends on whether you are signed in.

Signed in. Pressing Start for a new run creates a Stopwatch session in your account. Pausing is not sent to the server, so you can pause as often as you like. Pressing Reset closes the session. The server works out the credited time from when the run started, minus the time you paused. One run is credited for up to 24 hours.

A closed session counts only if it reaches 60 seconds. A counted run earns 1 point for each full minute and feeds your streak and your analytics. It also shows up in your session history with a Stopwatch label. A run shorter than 60 seconds is closed but earns nothing, and it does not count toward your streak. If you forget to press Reset, the run stays open until you start another timer, which closes it.

Signed out. The stopwatch runs and shows the same digits, but it creates no session on StudyClock's servers. Your stopwatch state stays in this browser. Signing in clears what the browser held for a signed-out visitor, so sign in before you press Start if you want the run saved.

Linking a run to a chapter or a task

When you are signed in, a box called Link this block appears under the stopwatch with two buttons: Link a chapter and Link a task. Signed-out visitors do not see it.

The chapter list can be searched by name or subject and loads more as you scroll. The task list shows only your pending tasks, so a finished task will not appear. Pick one or both before you press Start. The link is attached when the run is created, so changing the box halfway through does not move a run that has already started.

If a counted run was linked to a chapter, StudyClock adds that time to the chapter's focus total and adds one to its session count. It also marks the chapter as in progress. A linked task appears as a label on the run in your session history. This is how the stopwatch connects to the Chapter Tracker and to your task list.

What Sessions Today counts

Under the buttons there is a counter called Sessions Today. It goes up by one each time you press Reset with more than 30 seconds on the clock. At that moment you also get the chime, a browser notification if you allowed them, and a short message with your time in words.

This counter is not the same as your saved history, for two reasons. The counter uses a 30-second bar, while a saved run needs 60. And the counter is kept in your browser, not in your account, so your phone and your computer each keep their own number.

Despite its label, nothing in the current version resets the counter at midnight. A signed-in count is cleared when you sign out. A signed-out count is cleared when you sign in. Otherwise it keeps its number until you clear this site's data in your browser. Read it as a running tally for this browser, not as a daily figure. For a true count of today's runs, open your session history.

What happens if you reload or close the tab

The stopwatch keeps its state in your browser, so a reload does not lose your run. If the clock was running, it is still running when the page comes back, and the time you were away counts. A paused stopwatch comes back paused, at the same reading.

There is one limit. The page checks in every 15 seconds while the clock runs. If it has heard nothing from your browser for more than 5 minutes, because the computer was shut or asleep, only the first 5 minutes of that gap count. The rest is dropped. This stops a stopwatch you forgot about overnight from showing 10 hours of study.

If you open the stopwatch in a second tab, that tab shows the same clock and follows the first one, so pressing Pause in either tab pauses both. The page runs one stopwatch per browser, not two.

Timing a task to see how long it really takes

A stopwatch swaps the guess for a number. Here is a worked example for a past board paper with five long questions.

1. 1

   Press Start as you begin question 1.

2. 2

   When you finish each question, glance at the clock and write the reading in the margin. Do not stop the clock.

3. 3

   After question 5, press Pause and read the final time. If you are signed in, press Reset to save the run.

4. 4

   Subtract each reading from the one before it. Readings of 06:10, 15:45, 41:20, 48:05, and 58:30 give questions of 6:10, 9:35, 25:35, 6:45, and 10:25.

5. 5

   Plan the next attempt from that. The third question took 25 minutes 35 seconds, so give it a fixed budget and a rule to skip it and come back.

Because the stopwatch has no button that marks times, the margin notes do that job. Check the clock only at the end of a question. Watching it during the question turns the stopwatch into one more thing to look at.

Time a chapter of reading, a set of ten problems, or one practice essay the same way. After a few runs you know your real pace, and a study plan built on it fits the hours you actually have.

Full view, mini mode, and sound

On this page a small dock at the bottom right holds three buttons: Feedback, Mini mode, and Full view.

• Full view

  fills the screen with the stopwatch alone and hides the menus and the text below. Press Esc to leave.

• Mini mode

  keeps a small stopwatch on top of your other windows with Start, Pause, and Reset buttons. In Chrome and Edge it opens as a separate floating window. In other browsers it is a small panel you can drag around the page. It shows minutes and seconds only, without hundredths.

Sound and notifications are two toggles at the bottom right of the stopwatch card, and both are on every time the page loads. The chime plays when you press Start, and again on a Reset after more than 30 seconds. The notification appears only on that Reset. Turn the sound off in a library or a shared room.

Stopwatch or study timer

Both count up from zero and both save a counted run for a signed-in account under the same 60-second rule. The difference is how they show the time.

The study clock timer shows the running time on a large clock, which suits a clock you read from across a room. Not sure which style fits you? The focus test is a few quick questions that suggest a mode.

When a stopwatch is the wrong tool

• You want a fixed block.

  Set the countdown timer and treat zero as the end.

• You are sitting a timed mock exam.

  Set the countdown to the length of the paper so the clock matches the real thing.

• You want the end of a block to tell you.

  The stopwatch never rings on its own. A countdown or a Pomodoro timer gives you a point to work toward.

• You need to time two things at once.

  The page runs one stopwatch. Use a second device, or run the jobs one after the other.