Edit: Sept 18, 2019

Since new APIs are available, thought it would be helpful to point out that you can do this much more simply using toLocaleString options:

const numbers = [1, 1000, 2345.67, 21589.334719999995];
const options = { 
  minimumFractionDigits: 2,
  maximumFractionDigits: 2 
};
numbers.forEach(num => {
  const formatted = Number(num).toLocaleString('en', options);
  console.log(formatted);
});

---

original answer

To add the commas, you could use:

n = parseFloat(n).toFixed(2)
var withCommas = Number(n).toLocaleString('en');

Here is a fiddle

Did you add the locale to the toLocaleString function? for example javascript var number = 12345.543; number.toLocaleString('en') if i print the above code in the console it shows "12,345.543"

This seems to work

var formatNumber = function(num) {
    return parseFloat(num).toFixed(2).toLocaleString();
};

Did you try {{ "{:,.2f}".format(data[0]['amount'] }}? The very fine docs at https://jinja.palletsprojects.com/en/3.0.x/templates/#jinja-filters.format say In most cases it should be more convenient and efficient to use the % operator or str.format().

@cane van caneYou can limit it via regex and JavaScript combination. Eliminate the ‘,’ input and limit number from 2-10 along with decimal places (below code limits to 2 digits after decimal). If the input doesn’t match regex it would clear the text box. Add below code in Question JavaScript section.Qualtrics.SurveyEngine.addOnload(function() { var inputElement = jQuery("#" + this.questionId + " .InputText"); inputElement.on("blur", function() { var inputValue = jQuery(this).val(); // Regex for valid number format (2-9.99 or 10) var numberPattern = /^((10)|(2-9?))$/; if (!numberPattern.test(inputValue)) { // Invalid input jQuery(this).val(""); // Clear the input field or handle as needed } });});Hope it helps!Happy Holidays