EF_SaveFrameToPNG.jsx

/**========================================================================
 * ?                  EF_SaveFrameToPNG.jsx
 * @author         :  Eveline Falcão (https://evelinefalcao.com)
 * @email          :  hello@evelinefalcao.com
 * @version        :  1.0.0
 * @createdFor     :  Adobe After Effects CC 2024 (Version 24.1.0 Build 78)
 * @description    :  Quickly saves the current frame to PNG next to the project file.
 *========================================================================**/

(function saveFrameToPNG(){

    function currentTimeToFrames(currentTime, frameRate){
        return Math.round(currentTime * frameRate);
    }

    function padWithZeros(number, digits) {
        var str = number.toString()
        while (str.length < digits) {
            str = '0' + str;
        }
        return str;
    }

    var comp = app.project.activeItem;

    if(comp instanceof CompItem && comp != null) {
        var currentTime = comp.time;
        var frameRate = comp.frameRate;
        var currentFrame = currentTimeToFrames(currentTime, frameRate);
        var projectPath = app.project.file;

        if(projectPath != null){
            var stringProjPath = projectPath.toString().replace(".aep", "");
            comp.saveFrameToPng(currentTime, File(stringProjPath + "_" + padWithZeros(currentFrame, 6) + ".png"));
        } else {
            alert("Save your project to continue.")
        }
        
    } else {
        alert("Select your active Comp in the project panel or timeline.");
    }
})();