At this moment there is no such an option for the noUiSlider custom widget. We need to implement it in the widget source code - https://github.com/surveyjs/widgets/blob/master/src/nouislider.js#L80-L90

I've added this enhancement in our task list

ok cool, in the meantime I just added tooltips: wNumb({decimals: 0}), to get rid of the decimals

Did you modify the nouislider custom widget source code?

no, the surveyjs/libs/surveyjs-widgets.js file, that part here:

      var slider = __WEBPACK_IMPORTED_MODULE_0_nouislider___default.a.create(el, {
        start: question.value || (question.rangeMin + question.rangeMax) / 2,
        connect: [true, false],
        step: question.step,
        tooltips: wNumb({decimals: 0}),
        pips: {
          mode: question.pipsMode || "positions",
          ...

and this is how it looks:

Did you add the wnumb library? - https://refreshless.com/wnumb/

yes

Dear @tsv2013 and @msbt ,

i think, the issue is also with the data value of respective slider. Currently, the slider returns "4.00" (as string) in your example. However, you may want to have 4 (as number).

I fixed it via

slider.on("change", function() {
  question.value = wNumb({decimals: 0}).from(slider.get());
});

in the same file, however, this is not a permanent fix (as the file is updated with every npm install again).

Can we support the format option of the nouislider described here https://refreshless.com/nouislider/number-formatting/ ?

All the best

Maybe the even better fix would be to just cast it to a number?
Like so:

slider.on("change", function() {
  question.value = Number(slider.get());
});

We can't add a hard cast in our code because other users can use the float numbers. But you can modify the question value in the https://surveyjs.io/Documentation/Library?id=surveymodel#onValueChanging event handler

But casting it with Number(value) would certainly work, because currently it is a decimal number formatted as string, right?!

Can we have some kind of hook to format the visual output (i.e. the number shown next to the handle)?

And if that is not possible, maybe just a numeric input field to enter the number of decimals to be shown (i.e. "0" would remove the decimals completely). Internally you could rely on wNumb() as discussed above..