Map keys and values (keys being subjects and values being states that the subjects are in) and compress the mappings into small strings that can be decompressed into the original javacript object.

StateMapper64.js

function StateMapper(subjects,states) {
    var self = this;
    self.states = states || [];
    self.subjects = subjects || [];
    
    self.encode = function(z) {
        z = z.toString();
        var x = "0123456789";
        var u = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM!?";
        var s = x.length;
        var d = u.length;
        var v = 0;
        var n = z.length;
        for (var i = 0; i < n; i++) {
            v = v * s + x.indexOf(z.charAt(i));
        }
        if (v < 0) return 0;
        var r = v % d;
        var c = u.charAt(r);
        var q = Math.floor(v / d);
        while (q) {
            r = q % d; q = Math.floor(q / d); c = u.charAt(r) + c;
        }
        return c;
    };

    self.decode = function(z) {
        z = z.toString();
        var u = "0123456789";
        var x = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM!?";
        var s = x.length;
        var d = u.length;
        var v = 0;
        var n = z.length;
        for (var i = 0; i < n; i++) {
            v = v * s + x.indexOf(z.charAt(i));
        }
        if (v < 0) return 0;
        var r = v % d;
        var c = u.charAt(r);
        var q = Math.floor(v / d);
        while (q) {
            r = q % d; q = Math.floor(q / d); c = u.charAt(r) + c;
        }
        return c;
    };

    self.compress = function (data) {
        var str = "";
        for (var k in data) {
            var v = data[k];
            if (!self.states.includes(v)) {
                self.states.push(v);
            }
            if (!self.subjects.includes(k)) {
                self.subjects.push(k);
            }
            str += self.encode(self.states.indexOf(v));
        }
        return self.code = self.encode(str);
    };

    self.decompress = function (code) {
        code = code || self.code;
        if (!code) return ;
        var states = self.decode(code);
        if (states.length < self.subjects.length) {
            var l = self.subjects.length - states.length;
            for (var i = 0; i < l; i++) {
                states = "0" + states;
            }
        }
        states = states.split("");
        var out = {};
        states.forEach(function(state,index){
            out[self.subjects[index]] = self.states[parseInt(state)];
        });
        return out;
    };
}

/*
var sm = new StateMapper(["bob","joe","billy","boe"],["happy","sad","mad"]);
sm.compress({ bob: "happy", joe: "sad", billy: "mad", boe: "happy" }); // "1X" 
sm.decompress("1X");

*/