03 Enabling Developer options and USB debugging

This is the phone-side step that everything else depends on. It takes about a minute. Google's own instructions are at developer.android.com/studio/debug/dev-options and the brand guides in ../brand-guides/ adapt them per manufacturer, with source links and a verification date.

Why this exists

Android hides Developer options because most users never need them. USB debugging is the switch that lets an authorised computer talk to the phone through adb. Google states that to use adb over USB you must enable USB debugging in Developer options, and that on Android 4.2 and higher the Developer options screen is hidden by default until you enable it (developer.android.com/tools/adb).

Nothing about this step deletes data or voids a warranty. It does let any computer you authorise read and write app data, which is why the phone asks for confirmation and why chapter 05 shows how to revoke it afterwards.

Step 1 - Unlock Developer options

1. Open Settings on the phone.
2. Go to "About phone" (some brands: "My device", "About device", "About tablet").
3. Find "Build number". On Samsung it is under Software information; on Xiaomi the equivalent item is the OS version (developer.android.com/studio/debug/dev-options; mi.com/global/support/faq/details/KA-168765/).
4. Tap it seven times. Some builds ask for your screen-lock PIN after a few taps. That is normal.

What you should see: a toast or message such as "You are now a developer!" and a new "Developer options" entry, usually under Settings > System, or at the bottom of Settings on some builds.

If tapping does nothing: you are tapping the wrong item. It must be the build number or OS version, not "Android version".

Step 2 - Turn on USB debugging

1. Open Settings and search for "USB debugging" if you cannot find the menu; the search field is faster than hunting through nested menus.
2. On Android 9 and later the path is Settings > System > Advanced > Developer options > USB debugging. On earlier versions it is Settings > Developer options > USB debugging (developer.android.com/studio/debug/dev-options).
3. Leave the Developer options master switch at the top of that screen turned on. With it off, most options including USB debugging stop working.

What you should see: the toggle turns blue or green and a confirmation dialog may appear. Some brands add a second, separate prompt; the brand guide for your phone says whether yours does.

Step 3 - Some phones want a second switch

Three cases are worth knowing before you blame the cable:

• Huawei / Honor. Huawei's own support pages instruct users to enable "Allow ADB debugging in charge only mode" in addition to USB debugging when the USB debugging toggle will not stay on, and to disable "Allow connection via HDB" first (consumer.huawei.com/ca/support/content/en-us00407281/, consumer.huawei.com/en/support/content/en-us15501672/).
• Xiaomi / Redmi / POCO. Developer options on MIUI and HyperOS are reported to include an extra entry named "USB debugging (Security settings)". No Xiaomi-hosted document describing it was found on 2026-10-12, so this manual marks it unverified; the brand guide says where it is normally seen and what to do if ADB commands are refused without it.
• Samsung with Knox. Knox-managed devices can grey out USB debugging. Samsung's own developer documentation notes the greyed-out case; if the toggle cannot be changed, contact whoever manages the device.

Step 4 - Authorise the computer

1. Plug the phone into the computer (macOS: chapter 01, Windows: chapter 02).
2. Unlock the phone and watch for "Allow USB debugging?".
3. Compare the fingerprint only if you are in the habit of checking; otherwise tap "Always allow from this computer" and Allow.

What you should see on the computer: the device listed as device, not unauthorized. Google documents this dialog as the protection that stops adb commands running unless someone physically unlocks and approves (developer.android.com/tools/adb).

Step 5 - Turning it off again when you are finished

• To revoke one computer: Developer options > "Revoke USB debugging authorizations". The next connection asks for approval again (developer.android.com/tools/adb).
• To remove the whole screen: Developer options > top switch off. The entries keep their values but stop being active. Turn it back on when you need it.
• Turning USB debugging off does not delete anything and does not affect the recovered files.

Where to go next

• Wireless instead of a cable: chapter 04.
• The computer still sees nothing: chapter 05.
• Per-brand detail with source links: ../brand-guides/.