Steam AppID to SteamGifts GameID Converter

I'm confused. As far as I know, SG uses the same game IDs as Steam.
Are you talking about something else?

Okay, so I coded a scraper in JavaScript, which works pretty well.

var db = "";
var terminate = false;

function start() {
    for (var i = 0; i < 256; i++) {
        collect(String.fromCharCode(i), 1);
    }
}

function stop() {
    terminate = true;
}

function show() {
    console.log(db.slice(0, -1), db.slice(0, -1).split(",").map(function(x){return x.split(":");}));
}

function collect(query, page) {
    if (!terminate) {
        var data = { search_query: query, page_number: page, do: "autocomplete_game" };
        $.ajax({
            url: "/ajax.php",
            method: "POST",
            dataType: "json",
            data: data,
            success: function(json) {
                var html = json.html;
                if (html.length > 0) {
                    $("[data-autocomplete-id]", html).each(function() {
                        if ($(this).find("[href*='//store.steampowered.com/app/']").length > 0) {
                            var gameid = $(this).attr("data-autocomplete-id");
                            var appid = $(this).find("[href*='//store.steampowered.com/app/']").attr("href").split("/")[4];
                            var dbitem = appid + ":" + gameid;
                            if (db.indexOf(dbitem) == -1) {
                                db += dbitem + ",";
                                console.log("Added " + dbitem);
                            }
                        }
                    });
                    if ($(".fa-angle-right", html).length > 0) {
                        collect(query, page+1);
                    }
                }
            }
        });
    }
}

Run this code anywhere on SteamGifts, use start() to start scraping the data, use stop() to stop and use show() to show the data that was collected (format: appid:gameid). Here is data I collected for only running it a little while.

Edit:
Ran it a few hours and collected around 20K Game and DLC ID's.

If anyone is interested I am hosting a public JSON file / API where you can find AppID's with their corresponding game id's.