I simply added a local storage inspector bookmark to my chrome profile, so it gets sync to all devices. Now on any page, I just need to type its name, it will appear in dropdown, & clicking it exports all local storage used by current page or domain as json file.
Code of bookmarklet:
javascript:(function() { var backup = {}; for (i = 0; i < localStorage.length; i++) { var key = localStorage.key(i); var value = localStorage.getItem(key); backup[key] = escape(encodeURIComponent(value)); } var json = JSON.stringify(backup); var base = btoa(json); var href = 'data:text/javascript;charset=utf-8;base64,' + base; var link = document.createElement('a'); link.setAttribute('download', 'backup.json'); link.setAttribute('href', href); document.querySelector('body').appendChild(link); link.click(); link.remove();})()
Code of bookmarklet:
javascript:(function() { var backup = {}; for (i = 0; i < localStorage.length; i++) { var key = localStorage.key(i); var value = localStorage.getItem(key); backup[key] = escape(encodeURIComponent(value)); } var json = JSON.stringify(backup); var base = btoa(json); var href = 'data:text/javascript;charset=utf-8;base64,' + base; var link = document.createElement('a'); link.setAttribute('download', 'backup.json'); link.setAttribute('href', href); document.querySelector('body').appendChild(link); link.click(); link.remove();})()