How ozdor works, and who can see what

In one minute

• ozdor makes a safety copy of your WhatsApp chats in your own Google Drive, every night, and lets you read that copy in the app, even if WhatsApp stops working for you.
• Your chats stay readable only to you. They are locked with a key kept on your phone and in the recovery code you save. Your helper and Google cannot read them. (One exception, below: if you save the recovery code in Google's own password manager.)
• You can use ozdor on your own. If you connect it to your helper (the family member who invited you and runs ozdor), they see a daily "diary" of times and counts, so they can spot problems. Never your messages, your contacts' names or your photos. If you don't connect, they see nothing at all.
• You are trusting your helper, the way you would trust whoever looks after the family computer: they publish the app.
• The copy follows WhatsApp: what you delete in WhatsApp leaves the copy about a week later.
• You can stop at any time (see "If you stop").

What ozdor does on your phone

It reads the backup file WhatsApp writes on your phone each night, copies it to your Google Drive, and builds your copy from it on your phone. It asks for access to WhatsApp's backup folder (you choose it in Android's folder picker). Two permissions are optional: notifications (to tell you when something needs you) and contacts (only to show names instead of numbers, on your phone). Your own number comes from Google's number picker, which you confirm, or you type it. ozdor never contacts WhatsApp and never sends messages for you. It asks you once to let it run in the background (a setting in Android's own battery pages), reads whether that setting is on, and tells you on the phone if it is not; nothing about it is sent unless you connect to your helper (the diary, below).

ozdor works with one WhatsApp account on one Android phone: the standard WhatsApp app on the phone it is registered on. WhatsApp Business, a second account on the same phone and WhatsApp on linked devices are not supported yet.

Where your chats end up

Copies are never built on the server. Everything is built and kept on your phone and in your Drive. The server never has your messages, your contacts, your photos, your keys or your copy.

While your copy is being built, at night on the charger, an unlocked working copy sits in the app's private storage on your phone (which Android itself keeps encrypted). It is removed when the build ends; if the night was stopped, within about 9 hours of its start.

How ozdor uses your Google account

• What it asks for: permission to create files in your Google Drive and to see only the files it created (Google's drive.file access). It cannot see, open or change anything else in your Drive, and it does not ask for your email, contacts, calendar or anything else from your Google account.
• What it does with it: it keeps your safety copy there: the copy of WhatsApp's backup, your copy locked with your key, and, if you switch them on, your photos and files, locked. Nothing else.
• What it never does: it never sends your Drive files or anything from your Google account to anyone, never uses them for advertising, and never lets anyone read them. Your files are locked before they reach Drive.
• Removing it: uninstall the app and delete its folder in your Drive; you can also remove ozdor's access in your Google account's "Third-party apps and services". Nothing of your Drive is kept anywhere else.
• ozdor's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

Who you are trusting

• Your helper can read none of your chats. There is nothing readable on their server, and nothing at all if you don't connect.
• But they also publish the app. An update comes from them, and in principle an update could change what the app does. That is why ozdor is for family and close friends only: you are relying on your helper, the way you would rely on a family member who looks after the home computer. Close friends join on exactly the same terms as family. If that doesn't feel right, don't install it.
• Google holds the locked files in your Drive and knows when the app uploads them, like for any app that uses your Drive. The app can only see the files it made itself, not the rest of your Drive.
• If you save your recovery code in Google Password Manager (often the phone's default), the code lives in the same Google account as your locked files: someone who gets into that account could open your copy. The app prints the recovery sheet first for this reason. Prefer the printed sheet and another password manager, or turn on Google's on-device encryption for passwords.
• A notification service (ntfy) carries a short alert to your helper if a connected phone stops copying: your account's code (not your name), a number of hours and a few fixed words, nothing else.
• Nobody else. Not WhatsApp, not advertisers, not any analytics service.

The diary (only if you connect to your helper)

Every day a connected phone sends your helper a short diary, while ozdor is used only by family and friends, so they can see that copies are working and fix problems without asking you. It contains:

• WhatsApp's backup files on your phone: their names (which include dates), sizes and times, and when the app noticed and copied each;
• What the app did: how often it looked, what it copied and the outcome, and the reasons Android gave when it stopped or limited the app (fixed codes and counts), and whether the app may run in the background;
• The phone: the app and Android version, the phone's maker, Android's battery-saving class for the app, and estimates of when the phone was charging and asleep;
• Counts from building your copy: how many messages were added or removed.

It never contains a chat name, a contact's name, a message, a phone number or a photo; the phone checks this before sending. The diary and your account records are kept while ozdor is used only by family and friends, and deleted when you leave, or earlier if you ask.

Other people in your chats

Your copy contains messages from people who never agreed to this. Treat it like your WhatsApp itself. Your phone's contacts are used only on your phone, to show names; they are not sent anywhere.

The copy follows WhatsApp

• It mirrors WhatsApp, about a week behind. If you delete a message or a chat in WhatsApp, or WhatsApp no longer has it, it leaves the copy after a week (a safety week, in case it was a mistake). Edited messages show the latest text. This is not a place to keep what you deleted.
• Disappearing messages are never shown once their time is up. The locked files can still hold them until the next nightly update, and no older copy is kept for more than 7 days.
• View-once photos and videos are not copied: WhatsApp does not back them up.
• A safety brake: if a night would remove a large part of your copy (for example after a reinstall), nothing is removed until you confirm in the app.

Photos, videos and files

• Off unless you switch them on. You can switch on "Also copy photos and files"; the app first shows how much space they need and how much you have free in Drive. They can be big (many gigabytes) and may need a paid Google storage plan.
• They are locked before they leave your phone, like the rest.
• Photo locations: WhatsApp removes the location from photos before saving them, and Android blanks any that remain. The app doesn't change your files, so a video or document keeps whatever details its maker put in it, inside your locked copy.
• Only files your chats refer to are copied. Files left in WhatsApp's folder that no message refers to stay on your phone. Media you deleted from your phone before you started is gone.
• Photos and files of messages that leave WhatsApp leave your Drive too, about 8 days after your copy stops using them. The first large clean-up waits for your yes.

Your recovery code

Your copy can be opened with your recovery code. The app shows it once: print the recovery sheet, and save it in a password manager too. If you lose both the code and your phone, nobody, including your helper, can open your copy. They keep no copy. If you are banned from WhatsApp, you don't need the code: your phone still has the app and its keys. People you trust can use the code to read your copy after you; handing it over gives them full access now, not only later. Changing your WhatsApp key later takes nothing back: anyone who ever had your code or an earlier key keeps access.

A new phone, or a reinstall

On a new phone, or after reinstalling, ozdor finds your safety copy in your Drive and asks whether to use it on this phone. It only offers this when the phone proves it is yours (your recovery code or your WhatsApp key opens the copy) and you say yes. The old phone then stops adding to the copy, and nothing is deleted: the earlier copy is kept for at least 7 days.

If you stop, or something goes wrong

• Leave: tell your helper; they cut off your phone and remove your account and its diary from their server. You delete the app's folder in your Drive and uninstall the app.
• Lost or stolen phone: sign the phone out of your Google account, erase it with Find My Device, and tell your helper, who cuts that phone off from their server. The files in your Drive stay locked.
• WhatsApp bans you: nothing changes for the copy. Copies stop (WhatsApp makes no more backups), and your copy keeps everything up to the last night.
• Something is wrong with the app: the app says so in plain words, and if you're connected your helper sees it in the diary.

What it costs you

Wi-Fi data (about 230 MB to 1.6 GB per new backup, depending on your phone; mobile data only if you allow it, never while roaming), a little battery overnight, and space in your Drive.

What this is not

A private project for one family and its friends. It is not a WhatsApp product and not endorsed by WhatsApp; it uses only the backup file WhatsApp saves on your phone.

Questions

Ask your helper. This note will change as the project does, and the app will tell you when it does. Version 4.

Last updated: 8 November 2026. Version 4.