var allData; function fetchJSONFile(path, callback) { var httpRequest = new XMLHttpRequest(); httpRequest.onreadystatechange = function() { if (httpRequest.readyState === 4) { if (httpRequest.status === 200) { var data = JSON.parse(httpRequest.responseText); if (callback) callback(data); } } }; httpRequest.open('GET', path,false); httpRequest.send(); } fetchJSONFile('data.min.json', function(data){ allData = data; });