There are several ways to unlock a Samsung phone without its PIN or password, including using the Google account associated with the phone via the Android Device Manager and using Samsung's Find My Phone tool. It is also possible to unlock most phones by performing a factory reset, but this usually erases all information on the phone. Applicable methods vary depending on the phone's model and its version of the Android operating system.
The Android Device Manager is an app developed by Google to help manage Android-powered devices through the Device Manager website at Google.com. The app must be installed on a Samsung phone before it is locked to be useful for bypassing a lost or forgotten password or unlock pattern. If the application is present, logging into the Device Manager website allows a user to establish a temporary password and unlock the phone remotely. Samsung's Find My Phone app operates in a similar fashion to the Android Device Manager, though it operates through Samsung's website rather than through Google. Logging into Samsung's Find My Phone site presents users with an option to unlock the screens of their phones.
If a locked Samsung phone is running Android 4.4 or an earlier version, another method to bypass the lock screen on the phone is to fail to enter the correct unlock pattern five times in a row to activate the Forgot Pattern screen. Entering the Google account information associated with the phone at the Forgot Pattern prompt unlocks the phone. If neither the phone's PIN or unlock pattern or the account information for a Google or Samsung account associated with the phone are available, a factory reset may be the only option to restore access to the phone.