Every owner of a smartphone based on Android sooner or later encounters mysterious folders and files in the device’s memory, the names of which resemble technical terms. Among them there is often a term backup filesthat raises questions among inexperienced users: can they be deleted, do they take up extra space, and is it a virus. In fact, this is a fundamental mechanism of the operating system, ensuring the safety of your data in the event of failures or device changes.
In the context of the mobile ecosystem backup is the process of creating duplicates of critical information. These could be application settings, contact lists, call history, or even full system images. Backup files are created both automatically by services Googleand manually by the applications themselves to be able to restore the state of the app after reinstallation.
Understanding the structure of this data allows you to competently manage the (storage) of your gadget. Many users panic delete everything, freeing up space, but accidentally erase the only copy of important correspondence or progress in games. In this article we will analyze in detail what is hidden behind the name backup, where to look for these files in the file system and how to distinguish the desired archive from digital waste.
The technical essence of backup folders
The file system Android has a strict hierarchy in which each application runs in its own isolated environment, known as a sandbox. However, special directories are used to save data between work sessions or when updating the app. Most often, users find a folder with the name backup or files with the extension .ab (Android Backup) in the internal storage or on a memory card SD.
These files are compressed archives containing the data structure of a specific application or the system as a whole. Creation mechanism such copies may vary: some apps use built-in functions Android Backup Service, others write data to their own hidden directories. It is important to note that the storage format is often proprietary, that is, opening such a file with a simple text editor will not work without special utilities.
The location of this data depends on the version of the operating system. On older versions Android (before 10-11), access to system folders was freer, and users could see directory /data/local/backup or similar paths through file managers with superuser rights. In modern versions Android 12, 13, 14 access to system partitions is strictly limited by security policies Scoped Storage.
⚠️ Attention: An attempt to manually edit the contents of backup files using HEX editors can lead to irreversible damage to the archive. Restoring data from a damaged backup is often impossible even for professionals.
System backups often take the form of a single large file that is encrypted with the device key. This is done so that if your phone is stolen, an attacker cannot extract your personal information by simply copying files to your computer. Therefore, even if you find such a file on a memory card, you will not be able to read it on another device without the appropriate decryption keys.
Where to look for backup files in the smartphone's memory
Searching for backups begins with using a standard file manager, for example Files by Google or built-in conductor from the manufacturer (Samsung My Files, Xiaomi File Manager). The main path where user application backups are most often stored looks like Internal Storage/Android/data or Internal Storage/Android/obb, however, the archives themselves can lie deeper.
Let's consider the main locations where you should check for the presence of backup files:
- 📂 Internal storage root folder: Often applications create a directory with name
BackuporBackupsdirectly in the main directory for ease of access. - 📂 Application specific folder: Inside
Android/data/[application package name]/fileslocal copies of settings can be stored. - 📂 System directory: Path
/data/local/backupavailable only if available ROOT-rights and is used for full system backups via ADB. - 📂 Cloud local caches: Some messengers, for example WhatsApp or Telegram, store local copies of databases in folders
Databasesinside their directories.
To search for specific files, you can use the search function by name. Enter the word backup or extension .tar, .ab, .dbin the search bar. The system will show all matches. Be careful: some files may have random names, but are located in characteristic folders.
If you connect your smartphone to a computer via a USB cable in file transfer mode (MTP), you will only see the user part of the storage. System partitions containing critical backups will remain hidden. To access them, you will need special debugging tools or superuser rights.
Types of backup copies and their formats
Not all files marked backup are the same. In the ecosystem Android there are several standards and formats for data storage, each of which solves its own problems. Understanding the differences will help you decide which file can be deleted and which should be kept carefully.
The first type is local application backups. They are created by the apps themselves (messengers, launchers, games) and usually have a format .tar or proprietary .db. Such files are needed to quickly restore the app state in the event of a failure, without affecting the rest of the phone’s data. For example, the launcher can save the arrangement of icons to a file launcher_backup.tar.
The second type is full system images. They are created via a computer using the utility Android Debug Bridge (ADB). The command to create such a copy is as follows:
adb backup -apk -shared -all -system -f backup.abThe result of this command will be a file backup.abthat contains almost the entire contents of the phone. This is the most complete type of backup, but also the most difficult to manage. To unpack it on a computer, special scripts are required, since the format .ab is platform specific.
The third type is cloud synchronized copies. Although they are physically stored on servers Google Drive, their temporary cache files or authorization tokens may remain on the device. Deleting such local balances is usually safe, since the main data is in the “cloud” and will be pulled up again when you log into your account.
| File type | Extension | Where it is stored | Recovery difficulty |
|---|---|---|---|
| Local application backup | .tar,.db | Internal memory | Low (automatic) |
| Full system backup | .ab | PC or memory | High (software required) |
| Cloud snapshot | No (in the cloud) | Google Drive | Low (at login) |
| Whatsapp backup | .crypt14,.db | WhatsApp/Databases folder | Medium (same number required) |
Why can't .ab files open on my computer?
Files with the .ab extension have a specific Android Backup header structure. They are not ordinary ZIP archives. To view them on a PC, you need to use the Android Backup Extractor (ABE) utility, which removes encryption and converts the container into a standard TAR archive.
Is it possible to delete backup files
This is the most common question that arises when clearing memory. The answer is ambiguous and depends on where exactly the file is stored and whether you have an alternative copy of the data. If you see the folder backup in the root of memory and are sure that all your photos, contacts and settings are synchronized with your account Google, then deleting local duplicates can be safe.
However, if you delete files from specific application directories (for example, com.whatsapp or com.tencent.mm), you risk losing your chat history that was not uploaded to the cloud. Many users mistakenly believe that instant messengers always store everything on the Internet, but this is not true: local databases are often the only source of truth.
Before you click the “Delete” button, ask yourself three questions:
- 🤔 When was this copy last created? If the file is a year old, it is likely useless.
- ☁️ Is there a current copy in the cloud? Check your sync settings in the appropriate app.
- 📱 Are you planning to reset your settings? If so, then deleting backups will deprive you of the opportunity to quickly return the phone to working condition.
The safest thing to do is to delete old versions of backups, leaving only the most recent one. For example, instant messengers often store copies for the last 7 days. You can safely erase files with names like msgstore-2023-10-01.1.db.crypt14, leaving only the file without a date (current backup).
⚠️ Attention: Deleting system files from a folder
/datawithout root access is impossible using standard means. If you have accessed these folders through rooting, any mistake may brick your device. Proceed with extreme caution.
Before mass deleting files called backup, copy the suspicious folder to your computer or cloud storage. This will create a “rollback point” if you accidentally delete something important.
Instructions for creating a reliable backup
In order not to depend on random files in the phone’s memory, it is better to create your own, controlled backup. This ensures that you can recover your data at a critical moment. There are several ways to do this, from simple settings to advanced tools.
The simplest method is to use built-in tools Android. Go to Settings → System → Backup. Make sure that the switch is active and the correct account Googleis specified. Here you can start forced synchronization by clicking the button Start copying.
For more advanced users who want to save absolutely everything, including data from applications that do not support cloud backup, the method using ADB. You will need a computer, installed phone drivers and platform Platform-tools.
☑️ Preparing to create a full backup
After preparation, run the command in the computer terminal:
adb backup -apk -nosystem -shared -all -f C:\MyBackup\full_backup.abA confirmation request will appear on the smartphone screen. You must enter the encryption password (or leave it blank if you do not want to encrypt, although this is less secure) and click the confirm button. The process can take from 10 minutes to several hours depending on the amount of data.
An alternative for owners root access is the application Titanium Backup or its modern analogues. These tools allow you to “freeze” applications and create backups of each of them separately with a high degree of compression. This is an ideal option for custom firmware and frequent experiments with the system.
The regularity of creating backups is more important than their volume. It is better to make small backups of important data once a week than to try to save the entire phone once a year and face a lack of space.
Space problems and storage optimization
Backup files can take up gigabytes of free space, especially if you actively use instant messengers and play heavy games. Over time, duplicates, old versions of databases and temporary archives accumulate, which no longer carry a useful load.
To optimize space, it is recommended to use built-in cleaning tools. In Settings find the section Storage or Memory. The system will analyze the disk and offer to delete “old files” or “large files”. Often forgotten backups are hidden under this category.
It is also worth checking the settings of specific applications. In WhatsApp, for example, you can limit the number of local copies saved. Go to Settings → Chats → Chat backup and disable saving to Google Drive if you only need local copies, or adjust the frequency so that old files are overwritten by new ones.
If you are using a memory card SD, transfer folders with media files and heavy backup archives there. This will free up fast internal storage, which is critical to system performance. However, remember that memory cards are less reliable than built-in flash memory, and it is better to back up important backups to the cloud.
⚠️ Attention: The storage settings interface may differ depending on the manufacturer’s shell (MIUI, OneUI, ColorOS). If you do not find the described items, use the settings search by entering the query “memory” or “storage.”
Frequently asked questions (FAQ)
Is it possible to transfer the backup.ab file to another phone and restore the data?
Yes, this is possible, but with reservations. To restore, you need to connect the new phone to the same computer and run the command adb restore backup.ab. However, if the new phone has a different version of Android or differs applications (digital signatures), the restoration may not proceed correctly or some of the data will be lost.
Why does the backup folder constantly appear again after deletion?
This is normal behavior for many applications. They automatically create new backups every time you start them or on a schedule. To stop this process, you need to go to the settings of a specific application and disable the local backup or auto-backup function.
Is it safe to store backup files in the cloud (Google Drive, Yandex Drive)?
Yes, this is one of the most reliable storage methods. However, make sure you download the files to a secure folder or use a password to encrypt the archive before downloading. Do not store backup files in public domain, as they may contain personal information.
What to do if, when restoring from a backup, it says “data error”?
Most likely, the file is damaged or encrypted with a key from another device. If you made a backup via ADB with a password, make sure to enter the same password when restoring. Also check the integrity of the file: its size should not be 0 KB.
Will viruses or antiviruses delete backup files?
Ordinary antiviruses do not delete backup files, since they are not malware. However, some aggressive “cleaners” may mistake old archives for garbage. Always check the list of files before confirming cleaning in third-party utilities.