Switch between Wi-Fi and mobile data to see whether the network is the issue. Signal needs a stable internet connection for messages and calls.
Install the latest Signal version from the App Store or Google Play. Older builds can break after the service changes.
Allow microphone, camera, notifications, and background data. If notifications are delayed, battery optimization may be restricting the app.
If you cannot register, confirm your phone number includes the correct country code and can receive SMS or calls for verification.
If Signal is still broken after updates and permission checks, reinstall the app and complete the registration flow again.
Android and iOS often kill background app activity to save battery, which directly interferes with Signal's ability to receive messages and calls in real time. Go to your system Settings, find Signal under Apps or App Management, and disable battery optimization. On iPhones, enable Background App Refresh for Signal. This single setting fixes the majority of delayed notification complaints.
Signal registration is tied to your phone number. If you switch mobile carriers or port your number to a new SIM, complete the registration verification again inside Signal before assuming the app is broken. Keep your old SIM active until the port completes, because the SMS verification code will arrive on the old line during the transition period.
Signal's disappearing message timer and privacy settings can cause confusion when messages seem to vanish or conversations become unavailable. Check your default timer in Settings → Privacy → Disappearing Messages and confirm it matches your expectation. If you use Signal on multiple devices, verify that your linked devices list only shows trusted hardware to prevent sync issues.
Signal uses end-to-end encryption which can conflict with aggressive VPN configurations or DNS-level filtering. Temporarily disconnect your VPN and test Signal again. On Android, go to Settings → Network & Internet → Private DNS and set it to Automatic if you have a custom DNS provider configured. On iPhone, reset network settings by going to Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings. This clears any cached DNS entries that may be blocking Signal's servers.
If Signal cannot register or send SMS verification, the problem may be with your SIM card or APN (Access Point Name) settings. Check that your SIM is properly inserted and that your mobile data APN matches what your carrier provides. Go to Settings → Mobile Network → Access Point Names and compare the entries against your carrier's official APN documentation. An incorrect APN can block SMS delivery even when regular calls work fine.
Before doing a full uninstall, try resetting Signal's local data from within the app. On Android, go to Settings → Data and Storage → Clear local data. On iPhone, offload the app through Settings → General → iPhone Storage → Signal → Offload App. This removes cached corrupt files while keeping your chat history and account registration intact, saving you from having to re-verify your phone number.
Message sending failures usually occur due to network issues, outdated app version, or account registration problems.
Delayed notifications can be caused by battery optimization settings, Do Not Disturb mode, or background data restrictions.
Registration requires a working phone number and SMS capability. Make sure your number includes the right country code and can receive verification messages.
Call issues are typically caused by poor network connection, missing permissions, or firewall restrictions.
Repeated crashes often point to corrupted app cache or an incompatible operating system version. Clear the app cache from your device settings, then update to the latest OS version. If crashes persist after a clean reinstall, check the Signal community forums for known issues with your specific device model.
Signal needs SMS permission during registration to automatically read the verification code sent to your phone number. You can revoke SMS permission after registration completes. Without SMS permission during setup, you must manually enter the six-digit code from the text message, which leaves room for typo errors during verification.
Disappearing messages only apply to new messages sent after the timer is enabled. Existing messages in a conversation will not be deleted retroactively. Additionally, if the person you are chatting with has disabled disappearing messages on their end, the timer may not function as expected on shared group conversations. Verify the timer setting on both sides for consistent behavior.
Try the same service on a different device or network. If it works elsewhere, the issue is local to your device or network. If it fails everywhere, the service itself may be down - check Downdetector or the service's official status page to confirm.
Yes. A full restart (not just closing the app) clears stale connections, frees memory, and resolves the majority of intermittent glitches. Try this before deeper troubleshooting steps.
Open the App Store (iPhone) or Google Play Store (Android) and search for the app - if an Update button appears, tap it. On desktop apps, look for an About or Check for Updates option in the menu. Outdated apps often break after server-side updates.
If clearing the cache, updating, and restarting have all failed, reinstall the app as a last resort. A clean reinstall removes corrupted data, settings, and permissions that the standard fix steps cannot reach. Your account and saved data are stored in the cloud, so you won't lose anything by reinstalling.