I made a stopwatch that changes in real time.

Manipulate[Framed[Style[Dynamic@time, Bold, Black, 14],ImageSize -> {100, 50},
           Alignment -> Center],{{time, 3.14159, Style["", 12]}, 0, 4, 0.00001, 
           Animator,AnimationRunning -> False, AnimationRepetitions -> 1, 
           AnimationRate -> 1, DisplayAllSteps -> False, 
           AppearanceElements -> {"PlayPauseButton", "ResetButton"}} , 
           FrameMargins -> 25, AppearanceElements -> None] 

It works very well as a Notebook or CDF file. However, if you publish it to Wolfram Cloud, it will stop or slow down unlike real time.

Wolfram Cloud Page for STOPWATCH

How to make a stopwatch that can also be measured in real time on Wolfram Cloud? If it is impossible, it is also good to connect it in other ways, such as JavaScript. (However, I have to make a stopwatch up to 1/100000 seconds.)

  • $\begingroup$ When running Wolfram Notebooks or CDF files in the Wolfram Cloud, certain dynamic elements, such as the Animator, may not perform optimally due to limitations in the cloud environment. You might have to use JavaScript to solve your issue...That's the only solution I see to this problem unfortunatley $\endgroup$
    – Jakob
    May 10, 2023 at 4:42
  • $\begingroup$ When I say JS, I am not restricting you to just JS. You can also use Python or Java... JS is usually the language of choice when it comes to Web-stuff $\endgroup$
    – Jakob
    May 10, 2023 at 4:51

2 Answers 2


Here is something that might work. I know posting answers that might not be fully correct is against the guidelines, but being in a similar situation I found comforting to recived at least a hint of what I had to do.

I would add this code in Mathematica:

Hyperlink["JavaScript Stopwatch", "your/path/to/the/js/file/stopwatch.js"]

Button["Start Stopwatch", RunThrough["your/path/to/the/js/file/stopwatch.js", {"start"}], Method -> "Queued"]

Button["Stop Stopwatch", RunThrough["your/path/to/the/js/file/stopwatch.js", {"stop"}], Method -> "Queued"]

Dynamic[Refresh[Import["your/path/to/the/js/file/stopwatch.js", "String"], UpdateInterval -> 0.01]]

And this code in a separate .js file. To run and edit it, just use any code editor (I use VS Code) and execute it.

Edit: to execute raw JS code you would need a plug-in(runtime environment) called node.js. Just google how to install that, on mac you would simply type brew install node assuming brew is installed (if not install it from the web link or pull it from github using git clone)

var startTime, stopTime;

function startStopwatch() {
  startTime = performance.now();
  stopTime = 0;

function stopStopwatch() {
  if (startTime !== undefined) {
    stopTime = performance.now();

function getTime() {
  var elapsed = (stopTime || performance.now()) - startTime;
  return elapsed.toFixed(5);

function exportTime() {
  return getTime();

if (typeof global !== 'undefined') {
  global.start = startStopwatch;
  global.stop = stopStopwatch;
  global.export = exportTime;

Please keep in mind that when I said the answer might not be fully correct is because I am not fluent in JavaScript.

Remember to adjust the file paths in both code blocks to match your specific setup. By saving the Mathematica code in a notebook and the JavaScript code in a separate file (like stopwatch.js for instance, just note that .js extension is necessary), you can publish the notebook to the Wolfram Cloud, and the stopwatch should work with high precision timing.

I hope this helps and let me know if you have any questions.

  • $\begingroup$ Thank you for your answer. Unfortunately, I couldn't make a 1/100000 second stopwatch Java, nor could I connect to Wolfram Cloud. I need to study more. $\endgroup$
    – Milk
    May 14, 2023 at 1:33

This might not be the best way but so far I found the only way to have updates by the second is to use the Delayed function. Dynamic with Refresh works on the desktop but not in the cloud.

CloudPublish[Delayed[DateString[TimeObject[]], "Text", UpdateInterval-> 1]]

See Delayed function documentation for more detail.


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