Signal
What the default settings do
Signal encrypts every message, call, and attachment end to end by default, for every chat, with no separate mode to turn on and no unencrypted fallback to end up in by accident. There is no cloud backup that stores messages in plain form on a server, and no non-encrypted chat type the way some competitors offer for group or business messaging. If you use Signal at all, this protection is already active.
Signal also collects less metadata than most messaging apps. It does not build an advertising profile or sell data to third parties, and its own transparency reports describe the account information it holds as minimal: essentially your account creation date and last connection date. A feature called sealed sender, covered below, goes further and hides even the sender’s identity from Signal’s own servers for most messages.
Because of that starting point, this guide is short. There is a small set of real settings worth reviewing, mostly ones that add device-level or account-recovery protection Signal cannot switch on for you automatically, plus a couple of newer identity controls around phone numbers and usernames. There is no long list of default oversharing to fix here, because there isn’t one.
A reasonable privacy baseline
These settings are found in Settings within the Signal app, unless noted otherwise.
Account and device security
Registration Lock → On (Settings → Account → Registration Lock)
Registration Lock requires your Signal PIN before your phone number can be re-registered on a new device. Without it, anyone who takes over your phone number, through a SIM swap or carrier account takeover, could register it with Signal and receive your future messages. This is not on by default.
Screen Lock → On (Settings → Privacy → Screen Lock)
Screen Lock requires biometric authentication or your device passcode before Signal will open, separate from the phone's own lock screen. It protects your conversations if someone picks up your unlocked phone. Mobile-only; Signal Desktop has no equivalent.
Calls
Always Relay Calls → On (Settings → Privacy → Advanced, on mobile; Preferences → Calls on desktop)
By default, Signal tries to connect calls directly, which can reveal your IP address to the other person. Turning this on routes all calls through Signal's servers instead, hiding your IP at some cost to call quality since the connection is no longer direct.
Messages
Default Timer for New Chats → Set a timer, such as 1 week (Settings → Privacy → Disappearing Messages → Default Timer for New Chats)
This sets a default disappearing-message timer, from 30 seconds to 4 weeks, applied to chats you start after configuring it. Existing chats keep their own timer. Disappearing messages have always been available per chat; this just saves you setting one manually each time.
Generate Link Previews → On is reasonable, off is stricter (Settings → Chats → Generate Link Previews)
When on, pasting a link fetches a preview through a privacy-preserving proxy: the linked website never sees your IP, and Signal's servers never see the URL, since the connection is encrypted directly between your app and the site through that proxy. Turning it off avoids the request entirely, a reasonable extra step, but not a fix for a real leak in the default.
Phone number and identity
Who Can See My Number → Nobody (Settings → Privacy → Phone Number → Who Can See My Number)
This controls whether your phone number is visible on your profile to people who haven't already saved it in their contacts. Signal defaulted this to "Nobody" for most accounts starting in 2024, but it is worth confirming your account is actually set this way if it predates that change.
Who Can Find Me by Number → Consider Nobody, paired with a username (Settings → Privacy → Phone Number → Who Can Find Me by Number)
This controls whether someone who already has your phone number can find your Signal account and start a chat with it. The default is "Everybody." Setting it to "Nobody" means new contacts need your Signal username instead, at the cost of making you harder to reach for people who only have your number.
Username → Set one if you restrict phone number lookup (Settings → tap your profile name → Username)
A username lets people start a chat with you without ever knowing your phone number. It is not the display name shown in your conversations, is not visible to people you message, and can be changed or deleted at any time. It pairs naturally with restricting phone number lookup above.
Sealed Sender → Already on, no action needed for contacts
Sealed sender is a background feature, not a toggle to find: for messages between you and your contacts, Signal's servers handle delivery without seeing who sent it. A separate, optional setting under Advanced privacy extends this to strangers' messages too. That extension is off by default, so Signal can still apply spam filtering to strangers; turning it on trades that filtering for stronger anonymity on unsolicited messages.
Trade-offs
- Forgetting your PIN after enabling Registration Lock can lock you out of re-registering your number for up to 7 days.
- Screen Lock adds a small check each time you open Signal and isn’t available on Signal Desktop, so a stolen desktop session isn’t covered.
- Always Relay Calls reduces call quality by routing audio and video through Signal’s servers instead of directly.
- A shorter default disappearing-message timer means chat history you might later want will be gone unless you made an exception for that chat.
- Turning off link previews removes the preview card for links you send, even though the default fetch already avoids leaking the URL or your IP.
- Setting “Who Can Find Me by Number” to Nobody means people with only your number, and no username or existing chat, cannot start a new conversation with you.
- Turning on sealed sender for non-contacts reduces Signal’s ability to apply spam and abuse protections to strangers’ messages.
Who should not change these settings
- If you are prone to forgetting PINs and have no reliable way to store one, Registration Lock’s lockout risk may outweigh the SIM-swap protection it provides.
- If you share a device with family members who also need quick access to Signal, an additional Screen Lock may add friction that doesn’t match how the device is used.
- If call quality matters more to you than hiding your IP address, for example on work calls over an unreliable connection, leaving Always Relay Calls off is reasonable.
- If you rely on Signal as a searchable record of past conversations, for work or personal reference, a short default disappearing-message timer works against that and is best left off.
- If your account is a public, easily reachable contact point, such as for a business or tip line, keeping “Who Can Find Me by Number” set to Everybody and your number visible makes that possible.