Make gradient stops evenly spaced

Like Josh, I also wrote a script for distributing gradient stops back in 2021
https://github.com/creold/illustrator-scripts/blob/master/md/Color.md#distributegradientstops
 

The feature you’re requesting is just one of the things available in Astute Graphics’ Gradient Forge plugin. The Astute Graphics plugin suite for Illustrator is something that costs extra money, but if you need the feature pretty badly and need it now the plugins might be worth it. They are available on a free trial. I have the plugin suite mainly for the Vector First Aid plugin. But the Gradient Forge panel is pretty neat.

Just throwing this out there for reference... I had a hacky script that does basically what you are asking so I cleaned it up for posting here. It is not built-in or perfect and it doesn’t cover some edge cases but it works great for simple tasks. Cheers!

/*
EqualizeGradientStops.jsx for Adobe Illustrator
-----------------------------------------------
Evenly distributes the gradient stops of selected objects between the first and last stop.

Created in response to this question on the Adobe forum:
https://community.adobe.com/questions-652/make-gradient-stops-evenly-spaced-1629107

Related Docs:
* Gradients - https://ai-scripting.docsforadobe.dev/jsobjref/Gradients/
* Gradient - https://ai-scripting.docsforadobe.dev/jsobjref/Gradient
* GradientColor - https://ai-scripting.docsforadobe.dev/jsobjref/GradientColor
* GradientStops - https://ai-scripting.docsforadobe.dev/jsobjref/GradientStops
* GradientStop - https://ai-scripting.docsforadobe.dev/jsobjref/GradientStop
*/

//@target illustrator

(function () {
    if (!app.documents.length) {
        alert("No active document.");
        return;
    }

    var doc = app.activeDocument;
    var sel = doc.selection;

    if (!sel.length) {
        alert("No active selection.");
        return;
    }

    var processedGradients = [];

    for (var i = 0; i < sel.length; i++) {
        var item = sel[i];

        // Skip anything that does not have a fill.
        if (!item.filled) {
            continue;
        }

        var fillColor = item.fillColor;

        // Skip anything that is not filled with a gradient.
        if (fillColor.typename !== "GradientColor") {
            continue;
        }

        var gradient = fillColor.gradient;

        // A gradient swatch can be used by multiple objects.
        // Once we edit the swatch, all matching objects update automatically.
        if (contains(processedGradients, gradient.name)) {
            continue;
        }

        spaceGradientStopsEvenly(gradient);
        processedGradients.push(gradient.name);
    }

    function spaceGradientStopsEvenly(gradient) {
        var stops = gradient.gradientStops;
        var totalStops = stops.length;

        // Two-stop gradients are already evenly spaced.
        if (totalStops <= 2) {
            return;
        }

        var start = stops[0].rampPoint;
        var end = stops[totalStops - 1].rampPoint;
        var gap = (end - start) / (totalStops - 1);

        for (var i = 1; i < totalStops - 1; i++) {
            stops[i].rampPoint = start + gap * i;
        }
    }

    function contains(arr, value) {
        for (var i = 0; i < arr.length; i++) {
            if (arr[i] === value) {
                return true;
            }
        }

        return false;
    }
})();