How to find and turn on USB debugging mode on Nexus 4
AndroidAndroid Problem Overview
In settings on my Nexus 4 device there isn't any "USB debugging options" item. How do I find and turn on USB debugging mode on Nexus 4?
Android Solutions
Solution 1 - Android
Solution
To see the option for USB debugging mode in Nexus 4 or Android 4.2 or higher OS, do the following:
- Open up your device’s “Settings”. This can be done by pressing the Menu button while on your home screen and tapping “System settings”
- Now scroll to the bottom and tap “About phone” or “About tablet”.
- At the “About” screen, scroll to the bottom and tap on “Build number”
seven times.
- Make sure you tap seven times. If you see a “Not need, you are already a developer!” message pop up, then you know you have done it correctly.
Done! By tapping on “Build number” seven times, you have unlocked USB debugging mode on Android 4.2 and higher. You can now enable/disable it whenever you desire by going to “Settings” -> “Developer Options” -> “Debugging” ->” USB debugging”.
CONCLUSION
That was easy. The best part is you only have to do the tap-build-number-seven-times once. After you do it once, USB debugging has been unlocked and you can enable or disable at your leisure. Please restart after done these steps.
Additional information
Setting up a Device for Development native documentation of Google Android developer site
Update: Google Pixel 3
If you need to facilitate a connection between your device and a computer with the Android SDK (software development kit), view this info.
- From a Home screen, swipe up to display all apps.
- Navigate: Settings
> System 
> Advanced. - Developer options
.
If Developer options isn't available, navigate: Settings > About phone then tap Build number 7 times. Tap the Back icon 
to Settings then select System > Advanced > Developer options. - Ensure that the Developer options switch (upper-right) is turned on
. - Tap USB debugging to turn on
or off 
. - If prompted with 'Allow USB debugging?', tap OK to confirm.
> System 
> Advanced.
.
If Developer options isn't available, navigate: Settings > About phone then tap Build number 7 times. Tap the Back icon 
to Settings then select System > Advanced > Developer options.
.
or off 
.Doc by Verizon: Original source
Solution 2 - Android
Looking for About Phone in Settings. And scroll down till you see Build number. Tap here till you see Toast message tell you have just enable developer mode.
Back to settings, you can see options: "Developer options"
Solution 3 - Android
Step 1 : Go to Settings >> About Phone >> scroll to the bottom >> tap Build number seven times; this message will appear “You are now 3 steps away from being a developer.”
Step 2 : Now go to Settings >> Developer Options >> Check USB Debugging
this is great article will help you to enable this mode on your phone
Solution 4 - Android
Navigate to Settings > About Phone > scroll to the bottom > tap Build number seven (7) times. You'll get a short pop-up in the lower area of your display saying that you're now a developer. 2. Go back and now access the Developer options menu, check 'USB debugging' and click OK on the prompt. This Guide Might Help You : How to Enable USB Debugging in Android Phones
Solution 5 - Android
In case you enabled debugging mode on your phone and adb devices is not listing your device, it seems there is a problem with phone driver. You might not install the usb-driver of your phone or driver might be installed with problems (in windows check in system --> device manager).
In my case, I had the same problem with My HTC android usb device which installing drivers again, fixed my problems.
Solution 6 - Android
Open up your device’s “Settings”. This can be done by pressing the Menu button while on your home screen and tapping settings icon then scroll down to developer options and tap it then you will see on the top right a on off switch select on and then tap ok, thats it you all done.