2 working independent fields ?

[st1mset]

Do not tell me how to do it? I tried to do it like this, but in the end, one field controls both values

var $range = $(".js-range-slider"),
    $input = $(".js-input"),
    instance,
    min = 0,
    max = 4000;

$range.ionRangeSlider({
    type: "single",
    min: min,
    max: max,
    from: 0,
    onStart: function (data) {
        $input.prop("value", data.from);
    },
    onChange: function (data) {
        $input.prop("value", data.from);
    }
});

instance = $range.data("ionRangeSlider");

$input.on("change keyup", function () {
    var val = $(this).prop("value");
    
    // validate
    if (val < min) {
        val = min;
    } else if (val > max) {
        val = max;
    }
    
    instance.update({
        from: val
    });
});

var $range = $(".js-range-slider-to"),
    $inputTo = $(".js-input-to"),
    instance,
    min = 0,
    max = 2000;

$range.ionRangeSlider({
    type: "single",
    min: min,
    max: max,
    from: 0,
    onStart: function (data) {
        $inputTo.prop("value", data.from);
    },
    onChange: function (data) {
        $inputTo.prop("value", data.from);
    }
});

instance = $range.data("ionRangeSlider");

$inputTo.on("change keyup", function () {
    var val = $(this).prop("value");
    
    // validate
    if (val < min) {
        val = min;
    } else if (val > max) {
        val = max;
    }
    
    instance.update({
        from: val
    });
});

[IonDen]

Hi, simple. Second set of variables should be SECOND :) Now you just overwrite 1-st vars by new ones.

To avoid this, use unique names:

var $range_1 = $(".js-range-slider-1");
var $range_2 = $(".js-range-slider-2");

and so on for all other variables.

[st1mset]

did so, but that nothing has changed((

[IonDen]

I can't see what is wrong without a demo. Meanwhile, you can check this demo:
http://jsfiddle.net/IonDen/4k3d4y3s/

[st1mset]

http://jsfiddle.net/4k3d4y3s/113/
As I said, if you enter the value in any of the fields, it changes with 2 sliders

[IonDen]

Be more careful with naming. You are saving both sliders in 1 instance variable:

instance = $range_1.data("ionRangeSlider");

You should have 2 instances

instance_1 = $range_1.data("ionRangeSlider");
instance_2 = $range_2.data("ionRangeSlider");

[st1mset]

http://jsfiddle.net/4k3d4y3s/115/

Thanks, everything works, but that's just interesting why in 1 window you can not enter a value above 2000

[IonDen]

@st1mset, because you have max variable set 😄

max = 2000;

[st1mset]

so this is for 2 variables, and the problem is related to the first

[IonDen]

@st1mset, no. This is for both, you again rewriting vars. You should have different max and min:
min_1, max_1, min_2, max_2

[st1mset]

how it's complicated) thanks, work)