Signal FAQ

Yes. Signal registration still requires an existing phone number that can receive an SMS message or phone call. A username can later be used to connect with people without sharing that phone number.

Yes. Signal is free to use for private messaging, voice and video calls, groups, and supported sharing features. The service is developed by an independent nonprofit rather than funded through in-app advertising.

The verification code confirms control of the phone number used during registration. Never share this code with another person. It is separate from your Signal PIN, device passcode, and backup recovery key.

No. Registration starts on a supported Android phone or iPhone. Signal Desktop is added later as a linked device and does not create an independent desktop account.

A Signal PIN helps recover profile information, settings, contacts, and the block list, and it can also support Registration Lock. It is not a backup of your chat history and cannot restore lost messages.

Signal provides phone number privacy controls. By default, people you chat with do not see your phone number in your profile unless they already have it saved, and you can further control who can find you by number.

A username is an optional way for someone to start contact with you without needing your phone number. It is not your profile name, is not displayed as a permanent social handle, and can be changed or deleted.

Yes. A phone number is still required to register Signal. A username changes how people can initiate contact with you; it does not replace the phone number used for account registration.

By default, people who already know your phone number can use it to find you on Signal. You can change the phone number privacy setting so that people must know your exact username instead.

Yes. Signal usernames are optional and flexible. You can change or delete your username without ending existing chats, and your contacts and groups are not notified when you make that change.

A Signal account can have up to five linked devices in addition to the primary device. Linked devices can include supported desktop and mobile devices.

Open Signal Desktop to display a QR code. On the primary phone, open Signal Settings, choose Linked Devices, select the option to link a new device, and scan the QR code shown on the computer.

During first-time linking, Signal can synchronize your chats and the most recent 45 days of media from the primary phone. You choose whether to transfer message history during the linking process.

The primary phone does not need to stay continuously connected for linked devices to work, but it must come online at least once every 30 days. Linked devices can also become unlinked after extended inactivity.

Yes. You can review linked devices from Signal Settings on the primary device and unlink any device you no longer use or recognize.

Yes. Signal messages and calls use end-to-end encryption by default. Encryption is part of normal communication rather than a special mode that must be enabled for each chat.

Signal states that it cannot read the contents of your messages or listen to your calls because those communications are protected with end-to-end encryption.

Every one-to-one Signal chat has a unique safety number that can be compared with the other person to verify the security of that conversation. A safety number does not by itself verify someone’s real-world identity.

No. Signal does not use in-app advertising or affiliate marketing, and its communication service is not funded by building advertising profiles from private conversations.

Screen Lock uses the phone’s existing passcode or biometric authentication to restrict access to Signal on that device. It is separate from the Signal PIN used for account recovery features and Registration Lock.

Signal supports text, voice messages, photos, videos, GIFs, files, stickers, and other conversation features. Availability can vary by device and current app version.

A message can show as sent, delivered, or read. The read state appears only when both people have read receipts enabled.

Signal group chats can include up to 1,000 members. Groups also support invite links, QR codes, mentions, descriptions, and admin controls.

Signal group voice and video calls support up to 75 participants. Participants need to be members of the same Signal group and use a compatible current version of Signal.

Disappearing messages automatically remove messages from your devices after the selected timer expires. They help manage message history, but they cannot prevent another person from preserving content with another camera or device.

Signal offers optional secure backup and transfer methods, but your Signal PIN is not a message backup. The available recovery method depends on the device, backup type, and whether you prepared the backup before losing or replacing the phone.

Signal Secure Backups are an optional end-to-end encrypted backup system protected by a recovery key. They can restore supported message history when a phone is lost, damaged, replaced, or when moving between supported platforms.

Yes, when both phones are available and compatible. Direct device transfer works from Android to Android and from iPhone to iPhone, and it must be started during setup on the new device.

No. Direct device transfer does not work across Android and iOS. For supported cross-platform restoration, Signal Secure Backups are the relevant backup method.

No. Linked devices are not a recovery source for restoring message history back to a phone or another linked device. Restore and transfer options depend on backups or supported device-to-device transfer methods.

Registration Lock adds the Signal PIN as an additional protection when the phone number is registered again. It helps prevent someone who obtains an SMS verification code from easily taking over registration.

No. Signal does not know your Signal PIN and cannot reset or recover it for you. If Registration Lock is enabled and the PIN is forgotten, access can be delayed for up to seven days.

No. Do not share SMS verification codes, Signal PINs, or backup recovery keys with anyone. These credentials are designed to protect account registration or recovery.

No. Signal does not verify that a profile name represents a particular real-world person. For sensitive conversations, use contact information, safety numbers, and other trusted channels to confirm who you are communicating with.

Yes. Signal allows blocking from message requests, chats, groups, and privacy settings. Blocking stops direct contact, although shared-group behavior can differ because other group members still participate in the same conversation.

Check that the phone number is entered correctly in international format and can receive SMS messages or calls. Also confirm mobile network access and that messages from unknown senders are not being blocked.

The recipient may be offline, notification or battery settings may be interfering, or a safety number change may have occurred. Messages sent before a safety number change and left undelivered are not resent automatically.

A linked device can become unlinked if the primary phone does not come online for at least 30 days or if the linked device remains inactive for an extended period. Relinking requires access to the registered primary device.

Confirm the backup type, recovery key or passphrase, phone number, Signal version, network connection, and platform requirements. Secure Backups and on-device backups use different restore paths and are not interchangeable.

If preserving message history matters, confirm that you have a supported backup or transfer method before reinstalling. Signal does not keep a server-side copy of your conversation history that can simply be downloaded after a fresh installation.