Users of Android smartphones often encounter a situation when a file with the extension .backup, .ab or .tarappears on their device or computer, and a logical question arises: how to access the contents of this backup copy. Unlike the usual ZIP or RAR archives, system backups often have a specific structure, protected by encryption or proprietary headers, which makes them impossible to open using standard Explorer tools.
Understanding whether the file was created by the service is the key to successful data extraction. This could be a standard ADB utility, a messenger like WhatsApp, a cloud service from the manufacturer, or a third-party file manager. An incorrect attempt to rename an extension or open a file with inappropriate software can lead to damage to the data structure, so it is important to act methodically. which application or the file was created by the service is the key to successful data retrieval. This could be a standard ADB utility, a messenger like WhatsApp, a cloud service from the manufacturer, or a third-party file manager. An incorrect attempt to rename an extension or open a file with inappropriate software can lead to damage to the data structure, so it is important to act methodically.
In this material, we will analyze in detail the main types of backups found in the Android ecosystem, and provide step-by-step guide for decrypting and viewing them. You will learn what tools are needed to work with system images, how to extract messages from databases, and what nuances should be taken into account when restoring information on a new device.
Identifying the backup file type
The first step before attempting to open a file is to pinpoint its origin. The file extension often provides only a superficial clue, since different apps may use the same suffixes, for example .backup. The most reliable way is to analyze the size of the file and the path it is saved in the device memory or on the computer. If the file weighs several gigabytes and is located in the root of the memory or on an SD card, most likely it is a full system image created through the ADB utility. Such containers usually have the extension
If the file weighs several gigabytes and is located in the root of memory or on an SD card, most likely it is a full system image created via Recovery mode or ADB utility. Such containers usually have an extension .ab (Android Backup) or .tar. They contain a complete copy of the data section, including settings, applications and media files.
Smaller files, often found in application-specific folders (for example /WhatsApp/Databases), are local copies of chats or settings. They can be encrypted with a key linked to your Google account or phone number. To work with them, specialized decoders or the source application itself are required.
⚠️ Attention: Never try to edit binary backup files in text editors. This is guaranteed to violate the checksums and make the file unsuitable for recovery.
Before any manipulations, create a copy of the original backup file in a separate folder. This will allow you to roll back if the extraction process does not go as planned.
Working with the official Android Backup format (.ab)
Format .ab is the standard for backups created through a computer using the command adb backup. This container is a packaged data stream that includes a header indicating the Android version and encryption type, followed by compressed application content.
Direct opening of such a file in the archiver is impossible due to the specific header. To extract data you must use the utility Android Backup Extractor (ABE). It is an open source tool written in Java that correctly handles the package structure and unpacks it into .tar.
The conversion process requires the environment Java Runtime Environment to be installed on your computer. After downloading the ABE utility and the backup file, the operation is performed via the command line. It is important to understand that if the backup was encrypted with a password when it was created, without knowing this password, it will not be possible to decrypt the contents even with the help of special scripts.
java -jar abe.jar unpack backup.ab backup.tarAfter successfully executing the command, you will receive a standard TAR archive, which can be opened by any modern archiver, such as 7-Zip or WinRAR. Inside you will find folders appscontaining APK files and application data, as well as a directory shared with general files.
Why may the .ab file not open?
If an "Invalid header" error occurs during unpacking, this means that the file is damaged or has been created on a version of Android that uses a modified backup protocol (for example, some custom Xiaomi or Huawei firmware).
Data recovery from instant messengers (WhatsApp, Telegram)
Local backups of popular instant messengers have their own unique structure. In the case of WhatsApp, files are usually located in a directory /sdcard/WhatsApp/Databases and have names like msgstore-YYYY-MM-DD.1.db.crypt14. The number in the name of the extension indicates the version of the encryption algorithm.
To read such files without installing the application on the phone, there are special decryption utilities, but for their operation they often require a key file key, which is stored in a protected memory area/root access. Without this key, the database will remain a collection of unreadable bytes.
- 📱 Method through the app: Install WhatsApp on a clean device, log in with the same number and wait for the offer to restore a copy from local storage.
- 💻 PC method: Use third-party software like WhatsApp Viewer, having previously decrypted the database using Python scripts and a key.
- ☁️ Cloud method: If the file was synchronized with Google Drive, recovery occurs automatically the first time you set up an account on a new smartphone.
Users Telegram are in a more advantageous position, since this messenger stores the correspondence history on its servers by default. Local backup files in Telegram are rarely used and mainly concern the export of media files or settings, which are often saved in open JSON or HTML format.
☑️ Preparing to restore a chat
Extracting data from TAR and ZIP archives
Many smartphone manufacturers, such as Samsung, Xiaomi or OnePlus, use the format .tar or its compressed variations (.tar.gz) to create complete images of the system through proprietary utilities on a PC. These files often contain not only user data, but also system partitions.
Opening such an archive on a computer is quite simple using the app 7-Zip. However, the structure inside can be confusing: application data is often stored in folders with package names (for example, com.android.contacts) rather than human-readable names. To navigate inside the archive, it is useful to know the exact name of the application whose data you are looking for.
In some cases, the archive may be multi-volume or have a corrupted header structure if the creation process was interrupted. If a standard archiver gives an error, try using the utility WinRAR with the "Restore Archive" function, although success is not guaranteed in case of serious data damage.
| Extension | Compression type | How to open on PC | Features |
|---|---|---|---|
| .tar | No compression | 7-Zip, WinRAR | Clean file container |
| .tar.gz | Gzip | 7-Zip, PeaZip | High compression ratio |
| .ab | Specific | Android Backup Extractor | Requires conversion to TAR |
| .backup | Various | Depends on the creator | You need to look at the file header |
When working with large archives (>10 GB), make sure that there is enough free space on the disk where you are unpacking. The extraction process can take considerable time, especially if a slow HDD is used instead of an SSD.
The TAR format is a universal standard in the world of Linux and Android, so having a good archiver on your computer is a must for any advanced user.
Analysis of SQLite databases (.db)
Inside unpacked backups copies, you will often find files with the extension .db or .sqlite. These are databases in which applications store structured information: contacts, call history, settings and messages. You cannot simply rename them to text - you need a special viewer.
The app DB Browser for SQLiteis ideal for viewing the contents of such files on a computer. It's free, open source, and allows you to view tables, run SQL queries, and export data to CSV or Excel. This is the best way to extract specific information without restoring the entire application.
However, it is worth considering that some developers encrypt the contents of databases at the application level. In this case, when you open the file in the viewer, you will see empty tables or a set of incomprehensible characters instead of text. It is extremely difficult to bypass this encryption without access to the application source code.
⚠️ Attention: When exporting data from a SQLite database, carefully check the encoding. Cyrillic may appear as "krakozyabr" if the wrong encoding format is selected (usually UTF-8 is needed).
If you are not familiar with the SQL language, the DB Browser interface allows you to simply click on the "Browse Data" tabs to view the contents of tables. Look for tables with titles containing the words messages, contacts or logs.
Using third-party recovery apps
When standard methods do not work or require too much technical knowledge, specialized commercial products come to the rescue. apps like Dr.Fone, iMobie PhoneRescue or Tenorshare UltData offer a graphical interface for analyzing and extracting data from backups.
The main advantage of such solutions is automation. The app itself determines the file type, selects the desired decoding algorithm and offers you to select the data you want to save by checking the boxes. This saves time, but it is worth remembering that most of these apps are paid and often limit the number of files recovered in the trial version.
In addition, using third-party software always carries privacy risks. By transferring your backups to unknown apps, you potentially trust them with access to personal correspondence and photos. Always download software only from the official websites of developers.
For experienced users, an alternative is to use Android emulators on a PC, such as BlueStacks or NoxPlayer. In some cases, you can try to “slip” the backup file into the emulator data folder and run the corresponding application inside the virtual environment, forcing it to recognize the copy as native.
Common problems and ways to solve them
Even if all instructions are followed, users may encounter errors. The most common problem is version mismatch. A file created on Android 13 may not be processed correctly by utilities targeting Android 10 due to changes in the file system structure or encryption algorithms.
Another difficulty arises when trying to restore data to a device with a different firmware version or from a different manufacturer. System settings and file paths may differ, which will lead to the application simply not seeing the recovered data, even if the files are physically located in the desired folder.
If the file is partially damaged, you can try using archive recovery utilities, but the chance of success depends on the degree of damage. In critical cases, when the data is of high value, it is better to turn to data recovery professionals who have access to equipment for sector-by-sector memory reading.
Is it possible to open an .ab file on the smartphone itself without a computer?
You cannot directly open an .ab file on a smartphone using standard means. However, there are root applications, such as Swift Backup or specialized scripts in the terminal that can perform the decompression operation if the device has superuser rights and a command interpreter is installed.
Is it safe to upload backup files to online services for decryption?
Absolutely not It is recommended to upload backup copies containing personal information (photos, correspondence, passwords) to dubious online services. You cannot guarantee that the data will not be stored or used by third parties. Use only local software.
What should I do if I forgot the password for an encrypted backup?
Unfortunately, modern encryption algorithms (AES-256) used in Android are almost impossible to crack by brute force in a reasonable time. If the password is lost, the data is considered irretrievably lost, unless you have an old, unencrypted copy.
Is the process of opening a backup different on Samsung and Xiaomi?
The basic principle is the same, but proprietary utilities (Samsung Smart Switch, Mi Mover) create their own specific container formats. For Samsung, an encrypted archive is often used, which is best restored through the same Smart Switch utility on a PC, and not manually.
Is it possible to extract only photos from a full system backup?
Yes, this is possible. After unpacking the archive (for example, from .ab to .tar format), you can find the folder media or DCIM inside the archive structure and extract only it without restoring settings and applications.