How to use the auto-lock feature on Android

To protect your encrypted messages from falling into the wrong hands, you can enable the Auto-lock feature in the ProtonMail app.

This feature will prompt users to either enter a 4-digit PIN or to use biometrics to open ProtonMail. You can set your device to automatically lock every time you close your app, or after a set amount of time.

To enable auto-lock, follow these steps:

1. Go to Settings

2. Select Auto Lock

3. Tap on the toggle to enable the feature and then, enter a 4-digit PIN code. Select Create to save your code. 

4. Confirm your 4-digit code

Set up the auto-lock timer

Choose for how long ProtonMail can remain unlocked after you stop using the app by selecting Auto-lock timer.

Unlock using biometrics

You can also use your Android device’s face-recognition or fingerprint software to unlock ProtonMail by selecting Unlock using biometrics.

You can use the biometrics feature only after setting up a PIN.  Your device’s biometrics system will be used in this case to give you access to the app, instead of the PIN.

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  1. Chris

    This issue is one which concerns me as well. Currently, to get into my super secure email, all I have to do is press the protonmail icon on my phone and I’m in. If I have ProtonMail installed on my mobile device and it is lost or stolen, the only security my protonmail account has is whatever I set up on my phone. As far as I know. And I am not an expert at android by any stretch, but I suspect there is a fairly easy way to bypass these finger swipes (I no longer use this one since I know how easy it is to figure out the pattern) or pin codes (using now) or passwords (I hope I don’t have to do that, PIN is pain enough).

    On top of that, It seems every app I install wants permissions for everything on my phone, and some combination of these could steal my password, or prevent actually logging out, or sending the password to some hacker, or a million other things. I look for apps which have the minimum permissions required, but some still ask for more that I think they need or really want to give. But I do, just to have a valuable app. I hope I don’t have to wipe my phone, root it. and only use it as a phone and protonmail.

    So this ne version puts an optional (?) second layer of a 4 digit pin code between someone in the phone and my account. Is this one secure? since it is only 4 digits, is there a set number of trys before a delay and perhaps an email is sent to the user’s backup email address? It seems a little deranged to have built a web app with a mailbox password, and a strong vault password, then have a mobile app which till now has only required a push of an icon while the phone is unlocked.

    I agree it is important to have a mobile app because people expect it. But my phone is the device I trust least and most easily lost or stolen. When I start using protonmail seriously, I may not use the mobile app anymore. Then I have to count on my contacts not to either, because their lack of security exposes my messages to them….

    I’m sure you are very very aware of this problem and your adding this 4 digit pin seems a good start. I’ll wait and use it a while to see how it really works before commenting more.

  2. ProtonMail Support

    After 5 unsuccessful PIN entries you are logged out and you will need to log in with your passwords. We are working on adding more security options to the apps ass well.

  3. tsabrak

    Unlocking by fingerprint is available on ios, his will that this option is also available for Android phones that also have a fingerprint reader thank you .

  4. ProtonMail Support

    We will look into adding this option in the future.

  5. scjorge

    I’ve forgotten my PIN! :(
    how can I change/update it?

  6. ProtonMail Support

    You can use the Sign Out button at the bottom, to log out of your account, and then log in again. The PIN will be disabled when you log in.

  7. Open Haddock

    Hey Guys great feature…. on iOS that is. iOS lets the PIN be more than 4 digits. But not android…. please update the android app :)

  8. Claudio

    November 2017 and we still don’t have fingerprint unlocking for Android? C’mon guys, I was used to it on iPhone and now that I changed smartphone I can’t believe there is only the pin option…

  9. James

    I can’t enter a pin on the create a pin page because it won’t allow me to click on the number buttons. I am able to click the “Create” button but all the number buttons don’t register.

  10. ProtonMail Support

    Twilight and other similar apps that filter blue light can cause some security features to not work. If you are using such an app, you will need to disable it for the PIN keyboard to work.

  11. Patrick

    can’t use pin by choice, as it will not allow me to interact with PIN page. Android Samsung Prime J5 in use. when trying to establish a PIN, the page to create wont interact to allow me to create. How do I update Protonmail to android?

  12. ProtonMail Support

    Twilight and other similar apps that filter blue light can cause some security features to not work. If you are using such an app, you will need to disable it for the PIN keyboard to work.

  13. acer technical support

    I have an android mobile and I don’t have much more knowledge about android phones.I want to use a security feature on my phones for this query when I visit article .i get much more information about the lock feature in mobile phones.the information about auto-lock feature is very impressive and useful.

  14. dyna

    Fingerprint support would be great!

  15. marjorie jackson

    Hii friend,
    I am sharing here a little issue that is I’ve forgotten my PIN how can I change or update it? Can you help me?

  16. ProtonMail Support

    Please contact our support team at, or using the support form at

  17. LySioS

    Nice feature. But:

    If the device falls in the wrong hands, one can have a glance to the inbox simply by hitting the ‘switch all apps’ button.

    Thx for your work btw

  18. ProtonMail Support

    You can activate the Prevent taking screenshots option to avoid this. The ProtonMail app will show blank in the Recents menu with this option enabled.

  19. Anonymous


    Is it possible to create a PIN that is longer than 4-digits? If so, is there a maximum length for PINs?

    Many thanks for all of your hard work on this wonderful product! People all over the world appreciate the work that you are doing!

  20. ProtonMail Support

    No, the PIN cannot be longer than 4 digits.

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