// based on answer to question // http://stackoverflow.com/questions/4391575/how-to-find-the-size-of-localstorage (function showLocalStorageSize() { function stringSizeBytes(str) { return str.length * 2; } function toMB(bytes) { return bytes / 1024 / 1024; } function toSize(key) { return { name: key, size: stringSizeBytes(localStorage[key]) }; } function toSizeMB(info) { info.size = toMB(info.size).toFixed(2) + ' MB'; return info; } var sizes = Object.keys(localStorage).map(toSize).map(toSizeMB); console.table(sizes); }());