2017-02-24

How to back up your WhatsApp chats and photos safely on Android

This blog post explains how to make backups of your WhatsApp chats and photos safely on your Android device, and how to restore your backups. By safely we mean that you won't lose data unless you remove some backup files manually.

WhatsApp saves all chats to the WhatsApp/Databases folder on the phone's storage (sdcard), and it saves all photos and other media files to the WhatsApp/Media folder. (In fact, from the chats only the file WhatsApp/Databases/msgstore.db.cryptNNN may be needed, where NNN is an integer, currently 12.) If you make a copy of these folders, and copy them back to a new or reinstalled Android device before installing WhatsApp, then this effectively restores the backup, WhatsApp will recognize and use these files the first time it's installed (you need to tap on the Restore button within WhatsApp). See this FAQ entry for more information on restoring WhatsApp backups on Android.

WhatsApp supports creating backups to Google Drive (automatically, every day), and restoring those backups when the app is (re)installed. This sounds like convenient and safe, but it's not safe, you can still lose your chat history and photos (see below how). So if you care about your WhatsApp chat history and photos, and you need an automated backup for them, here is my recommendation: use the FolderSync Lite free Android app to make automatic backups to the cloud (it supports Google Drive, DropBox and more than 20 other cloud providers). To restore the backup, you can use FolderSync Lite, or you can download the files and copy them to your Android device manually.

Here is how to set up FolderSync Lite on Android for automatic backups of WhatsApp chats, photos and other media:

  1. Create a Google account, open Google Drive, create a folder named FolderSyncBackup-WhatsApp, and within it create subfolders Databases and Media (both case sensitive). It can also be done similarly on Dropbox instead, but this tutorial focuses on Google Drive.
  2. Install FolderSync Lite to your Android device.
  3. Add your Google account to FolderSync lite.
  4. Create a folderpair for backing up chats:
    • Account: your Google account
    • Unique name: wad
    • Sync type: To remote folder
    • Remote folder: /FolderSyncBackup-WhatsApp/Databases/
    • Local folder: .../WhatsApp/Databases/
    • Use scheduled sync: yes
    • Sync itnerval: Daily
    • Copy files to time-stamped folder: no
    • Sync subfolders: yes
    • Sync hidden files: yes
    • Delete source files after sync: no
    • Retry sync if failed: yes
    • Only resync source files if modified (ignore target deletion): yes
    • Sync deletions: no
    • Overwrite old files: Always
    • If conflicting modifications: Skip file
    • Use WiFi: yes
    • (Many settings below are fine, skipped here.)
  5. Save the folderpair, and do the first sync manually.
  6. Create a folderpair for backing up media files, including photos:
    • Account: your Google account
    • Unique name: wam
    • Sync type: To remote folder
    • Remote folder: /FolderSyncBackup-WhatsApp/Media/
    • Local folder: .../WhatsApp/Media/
    • (Subsequent settings are the same as above.)
  7. Save the folderpair, and do the first sync manually.
  8. Optionally, you can turn of WhatsApp's automatic backup to Google Drive in the WhatsApp app's chat settings.
  9. To remove the WhatsApp's automatic backup files from Google Drive, go to Google Drive, click on the gear icon (Settings), click on Settings, click on Manage Apps, find and click on the Options off WhatsApp Messenger, click on Delete app data, and then click on Disconnect from Drive.

WhatsApp saves all chat history so far to a new file every day (file name pattern: WhatsApp/Databases/msgstore-????-??-??.*.db.crypt*). These files will accumulate and fill up your Google Drive quote in a year or two, so you may want to remove old files. You can do it manually on the Google Drive web UI, just visit the FolderSyncBackup-WhatsApp/Databases folder, select old files (by date), and remove them. Alternatively, you can automate removal using an Apps Script. Here is how:

  1. Visit http://script.google.com/
  2. You see a script editor window. Remove the existing code (function myFunction() { ... }).
  3. In the File / Rename... menu, rename the project to script to remove old WhatsApp backups
  4. Copy-paste the following code to the script editor window:
    var FOLDER_NAME = 'FolderSyncBackup-WhatsApp';
    // Please note that msgstore.db.crypt12 will always be kept in addition to the dated files.
    var MINIMUM_DBS_TO_KEEP = 8;  // A value smaller than 8 doesn't make sense, WhatsApp keeps that much, and these files would be reuploaded by FolderSync.
    var USE_TRASH = true;
    var DO_DRY_RUN = false;
    
    function getSingleFolder(foldersIter) {
      var folder = null;
      while (foldersIter.hasNext()) {
        if (folder != null) throw new Error("Multiple folders found.");
        folder = foldersIter.next();
      }
      if (folder == null) throw new Error("Folder not found.");
      return folder;
    }
    
    function getAll(iter) {
      var result = [];
      while (iter.hasNext()) {
        result.push(iter.next());
      }
      return result;
    }
    
    function compareByName(a, b) {
      var an = a.getName(), bn = b.getName();
      return an < bn ? -1 : an == bn ? 0 : 1;
    }
    
    function removeOldWhatsAppBackups() {
      Logger.log('<removeOldWhatsAppBackups>');
      Logger.log('Config FOLDER_NAME=' + FOLDER_NAME);
      Logger.log('Config MINIMUM_DBS_TO_KEEP=' + MINIMUM_DBS_TO_KEEP);
      Logger.log('Config USE_TRASH=' + USE_TRASH);
      Logger.log('Config DO_DRY_RUN=' + DO_DRY_RUN);
      // var folders = DriveApp.getFolders();  // Also lists subfolders.
      var folder = getSingleFolder(getSingleFolder(DriveApp.getRootFolder().getFoldersByName(FOLDER_NAME)).getFoldersByName('Databases'));
      var files = getAll(folder.getFiles());
      var sortedFiles = [];
      var i;
      for (i = 0; i < files.length; ++i) {
        var file = files[i];
        var name = file.getName();
        // Logger.log(name + ': ' + file.getDateCreated());  // No last-modification time :-(.
        if (name.match(/^msgstore-\d\d\d\d-\d\d-\d\d[.]/)) {
          sortedFiles.push(file);
        }
      }
      sortedFiles.sort(compareByName);  // The name reflects the date. Earlier file first.
      var toKeep = MINIMUM_DBS_TO_KEEP;
      if (toKeep < 1) toKeep = 1;
      for (i = 0; i < sortedFiles.length - toKeep; ++i) {
        var file = sortedFiles[i];
        // Logger.log('?? ' + file.getName() + ': ' + file.getSize());
        // A 100-byte decrease in file size is tolerable, can be a compression artifact.
        if (file.getSize() - 100 < sortedFiles[i + 1].getSize()) {
          if (DO_DRY_RUN) {
          } else if (USE_TRASH) {
            file.setTrashed(true);
          } else {
            DriveApp.removeFile(file);
          }
          // Utilities.sleep(100); // Prevent exceeding rate limit (currently 10 requests per second). Is it still in effect?
          Logger.log('-- Removing: ' + file.getName() + ': ' + file.getSize());
        } else {
          Logger.log('Keeping: ' + file.getName() + ': ' + file.getSize());
        }
      }
      for (; i < sortedFiles.length; ++i) {
        var file = sortedFiles[i];
        Logger.log('Keeping recent: ' + file.getName() + ': ' + file.getSize());
      }
      Logger.log('</removeOldWhatsAppBackups>');
    }
  5. Click on the File / Save menu to save the script.
  6. Open the Resources / All your triggers menu window, choose Add a new trigger, add this: removeOldWhatsAppBackups, Time-driven, Day timer, 5am to 6am, also add a notification to yourself in e-mail, sent at 6am.
  7. Click on Save to save the triggers.
  8. You may wonder if this Apps Script deletes chat backups in a safe way. You have to decide this for yourself. It keeps the 8 last backups, and it also keeps all backups after which the backup file size has decreased. This latter condition prevents the data loss case described below (in the next section).

That's it, automatic and safe backup of WhatsApp chats, photos and other media files to Google Drive is now set up using FolderSync Lite.

Is WhatsApp's built-in backup to Google Drive safe?

No it isn't, you can lose all your data in some cases. The data loss happened to a friend in Feb 2017 in the following way:

  • The Android phone was lost, thus the WhatsApp folder on the phone wasn't available.
  • There was a working and recent backup on Google Drive.
  • When WhatsApp was installed to a new phone, it started restoring the backup from Google Drive.
  • Shortly after the start of the restore, the internet connection broke and the restore was aborted. Only a little part of the messages were restored.
  • The owner of the phone didn't notice that many chats are missing, and started using WhatsApp.
  • Within 24 hours, WhatsApp created a new backup to Google Drive, overwriting the old, full data with the new partial data. At this point the majority of the old chats got lost.
  • A couple of days later the owner of the phone noticed, but it was too late.

If WhatsApp's built-in backup to Google Drive had been written in a way that it never overwrites old backups, it would have been possible to reinstall WhatsApp and restore all the chats without data loss. Unfortunately the users of WhatsApp have no control on how WhatsApp does backups. But they can use an alternative backup method which never loses data (see the method with FolderSync Lite above).

Another way to safely restore WhatsApp's built-in backup from Google Drive would be downloading it from Google Drive first, and keeping a a copy until WhatsApp has successfully restored everything on the new Android device. Unfortunately this is impossible, because it's impossible for the user to download their own backup from Google Drive (!), because it is saved to a hidden app folder, which only the WhatsApp app can read and write, and the user is unable to access it (apart from deleting it). This StackOverflow question has an answer which describes a cumbersome and fragile way for downloading, but this can easily change in the future, so I don't recommend it for general use. I recommend the method with FolderSync Lite above instead, which makes it easy for the user to see and download their WhatsApp backup from Google Drive.