Signal Backups (server backup)
Signal Backups store your messages and media on Signal’s servers. This is a paid feature available as part of a Signal subscription.What’s included
Server backups contain:- All your messages and threads
- Media attachments (photos, videos, voice notes, documents) — included with the paid tier
- Call history
- Sticker packs
- Notification profiles
- Chat folders
- Contact information for your Signal contacts
- App settings
Backup tiers
Moving from the free tier to the paid tier resets the “initial backup completed” flag. Signal performs a fresh full upload when you upgrade.
Enable Signal Backups
1
Subscribe to Signal
Go to Settings → Backups and follow the prompts to subscribe. Signal Backups require an active Signal subscription purchased through Google Play.
2
Set backup frequency
Choose how often Signal should back up automatically: Daily, Weekly, Monthly, or Manual. Signal schedules the next backup time based on your selection.
3
Choose Wi-Fi or cellular
By default, backups run on Wi-Fi only. Enable Back up using cellular data if you want backups to run on a mobile connection.
4
Wait for the initial backup
Signal uploads your backup in the background. A progress indicator appears in Settings → Backups. The first backup may take longer depending on your message and media volume.
Backup encryption
Signal Backups use two separate encryption keys:- Message backup key — derived from your Account Entropy Pool (AEP), which is tied to your Signal registration. This key protects the backup’s message frame.
- Media root backup key — a randomly generated key stored on your device that protects backed-up media files.
Backup key verification
Signal periodically prompts you to verify your backup key. You can check the key and the last verification time in Settings → Backups → Backup key. Verifying the key confirms that the key stored on your device matches the one used to encrypt your backup.Storage and errors
Signal monitors available remote storage space. If your backup exceeds available space, Signal shows a warning in settings. To resolve it, you can delete old messages or media from your chats to reduce backup size. Backup creation errors fall into four categories:- Transient — typically a network issue; Signal retries automatically.
- Validation — the backup file failed integrity checks; may require an app update.
- Backup file too large — delete some messages to bring the backup within size limits.
- Not enough disk space — free up local storage so Signal can stage the backup file.
Local backups
Local backups write your message history to a folder on your Android device (or a location you choose, such as an SD card or a cloud-synced folder). They are independent of any Signal subscription.Enable local backups
1
Open backup settings
Go to Settings → Backups → Local backup.
2
Choose a backup folder
Signal prompts you to pick a destination folder using Android’s system file picker. The folder URI you choose is saved so Signal can write subsequent backups to the same location.
3
Enable automatic backups
Toggle on Enable local backup. Signal will create backups automatically according to its internal schedule and store progress in app state so it survives restarts.
4
Create a manual backup
Tap Create backup now to trigger an immediate backup. Signal shows real-time progress through several phases: account data, recipients, threads, calls, stickers, notification profiles, chat folders, and messages.
Backup file format
Local backups use the Signal backup v2 format. Each backup snapshot consists of:- A metadata file containing a versioned header and an encrypted backup ID
- A main archive containing the message frames (encrypted)
- A files manifest listing all media file names included
Signal also supports exporting a plaintext local backup as a ZIP file containing a
metadata.json, a main.jsonl message stream, and a files/ directory of attachments. This format is useful for data export and analysis but is not encrypted at rest.Backup passphrase (legacy local backups)
Older versions of Signal local backups used a 30-digit passphrase. If you have a legacy.backup file, you need this passphrase to restore it. The passphrase was displayed once when you enabled local backups.
Restoring from a backup
Restore from Signal Backups (server)
1
Install Signal on your new device
Download and open Signal. During registration, Signal detects that a server backup exists for your account.
2
Sign in and initiate restore
Complete phone number verification. Signal prompts you to restore from your backup. You may also trigger restore via a QR code scan from your old device.
3
Download your backup
Signal downloads and decrypts your backup. Message frames restore first; media downloads in the background. You can use Signal while media is still downloading.
You can choose to skip media restore if you want to save storage space or data. Skipped media cannot be recovered later.
4
Verify backup key
After restore, Signal prompts you to verify your backup key to confirm the restored data is intact.
Restore from a local backup
1
Install Signal on your new device
Open Signal and proceed through registration.
2
Select local backup
On the restore screen, tap Restore from local backup and grant Signal access to the folder containing your backup snapshot.
3
Select a snapshot
If multiple snapshots exist, Signal lists them by timestamp. Select the snapshot you want to restore.
4
Enter your backup key or passphrase
Signal uses your Account Entropy Pool to decrypt the backup. For legacy
.backup files, enter your 30-digit passphrase when prompted.5
Wait for import
Signal imports all message frames. Attachments linked in the backup are restored if the media files are present in the backup folder.
What is NOT included in backups
The following items are not backed up by either method:Signal PIN
Your Signal PIN is stored in Secure Value Recovery and is not part of message backups.
Safety number verifications
Verified safety numbers are not transferred; you need to re-verify after restoring.
App settings (partial)
Some Android-specific settings may not be restored. Signal imports a basic set of settings from the backup where available.
Linked device sessions
Linked device pairings are not preserved. Re-link your tablet or desktop after restoring.
Transferring directly between devices
If both your old and new phones are available at the same time, you can use Signal’s device transfer feature instead of a backup:1
Open Signal on your new phone
Tap Transfer from Android device on the registration screen.
2
Scan the QR code from your old phone
On your old phone, go to Settings → Account → Transfer account to new device and display the QR code.
3
Transfer over Wi-Fi
Signal transfers your messages and media directly between devices over a local Wi-Fi connection. No data passes through Signal’s servers during a device transfer.