Signal Android can be configured as your default SMS/MMS app in addition to supporting end-to-end encrypted messages and calls with other Signal users.
- Learn how to distinguish when communication is private (Signal message) or insecure (SMS/MMS).
- See steps for troubleshooting insecure MMS below.
See additional steps for:
Insecure media and group messages (MMS) are transmitted through your mobile plan and incur fees as set by your mobile plan.
- Confirm you have SMS (text) or MMS (group and media) as part of your mobile plan.
- Check the credits on your mobile plan to send SMS/MMS. Add credits if your balance is empty.
- Confirm that you are connected to your mobile network.
- Enable Signal Settings > Chats > SMS and MMS > 'WiFi Calling' compatibility mode and try again.
- Confirm all the application permissions are enabled for Signal.
- For some devices, restart your phone and view the message again.
- Check your other SMS/MMS app. Even if the other app is not open, it may retrieve the MMS before Signal can.
- Signal has a size limit of 300kb for sending MMS.
- Reconfigure the APN settings for your phone.
- You may need to repeat this after every OS update and this impacts any MMS app on your phone.
- Steps to resolve vary by model phone, OS, and provider.
- T-Mobile's Support Page
- Search for your provider specific page
- If the Network was set to automatically select, turn that off and check if the APN type saved in the settings was 'default,supl'. Change it to 'default,dnn,supl,mms' or 'default,dnn,supl,sms' and see if you experience different results.
- Google-Fi users can switch the underlying carrier. Here are some dialpad shortcuts you can use to switch out the carrier that’s backing your Fi connection.
- To see your current carrier info: ##fiinfo##
- Switch to T-Mobile: ##fitmo##
- Switch to Sprint: ##fispr##
- Switch to US Cellular: ##fiusc##
- Switch back to automatic: ##fiauto##
- Temporarily remove Signal as your default messenger and set it back.
- In Signal, tap your profile > Chats > SMS and MMS > tap Use as default SMS app to select another app. Then, return to Signal and tap Use as default SMS app again to enable.