Does fixing the HyperOS keyboard gap need root?

No. Plain adb shell (uid 2000) is enough. No unlocked bootloader, no Magisk, no custom recovery.

Will it break banking apps, SafetyNet or Play Integrity?

No. Nothing is deleted and no partition, signature or system property changes. The bootloader stays locked and verified boot stays green. It is a per-user package disable.

Do I lose gesture navigation after removing the overlay?

No, but you must re-pick Gestures once in Settings > Home screen > System navigation, because HyperOS falls back to 3-button when the overlay disappears. Xiaomi's gesture engine runs off force_fsg_nav_bar, which is independent of the framework navigation_mode value.

Why doesn't Hide full screen indicator remove the keyboard gap?

That setting only hides the white pill. It does not change config_imeDrawsImeNavBar, so the keyboard still builds its own navigation row and still reserves the inset. The pill disappears and the gap stays.

Yes. cmd package install-existing restores it, and the script also re-arms the overlay with cmd overlay enable-exclusive, because install-existing alone brings the package back disabled and strands the phone in 3-button mode.

Will an OTA update undo the fix?

A full OTA or a factory reset can restore the overlay for user 0. Run apply again afterwards. A normal reboot does not undo it.

Fix the HyperOS 3 Keyboard Gap — Remove the Black Bar Under the Keyboard (Xiaomi, Redmi, POCO)

Quick start

Install platform-tools, turn on USB debugging, plug the phone in:

# Linux / macOS / Git Bash / WSL
git clone https://github.com/IRDcode/hyperos-keyboard-gap-fix.git
cd hyperos-keyboard-gap-fix && chmod +x fix-keyboard-gap.sh

./fix-keyboard-gap.sh          # read-only: are you even affected?
./fix-keyboard-gap.sh apply
./fix-keyboard-gap.sh verify

# Windows PowerShell
.\fix-keyboard-gap.ps1
.\fix-keyboard-gap.ps1 -Action apply
.\fix-keyboard-gap.ps1 -Action verify

Or just the one line, if you already know what you are doing:

adb shell pm uninstall --user 0 com.android.systemui.gesture.line.overlay

Then finish on the phone — do not skip this. HyperOS drops to 3-button navigation the moment the overlay goes away. Open Settings → Home screen → System navigation, pick Gestures again, and switch Hide full screen indicator ON. Gestures come back; the gap does not.

No reboot needed. If one particular keyboard still shows the gap, force-stop that app once so it re-measures its window.

Is this your bug?

Black bar or strip under the keyboard, appeared after the HyperOS 3 update
Keyboard floats instead of sitting flush at the bottom edge
An extra row containing only a ⌄ arrow under Gboard or SwiftKey
Turning Hide full screen indicator off and on changes nothing
Switching keyboards, clearing keyboard data and changing themes all change nothing
Persian: نوار مشکی زیر کیبورد، فاصله‌ی اضافه‌ی پایین صفحه، فلش پایین زیر کیبورد

Not this: a gap above the keyboard (that's the app's layout), or the navigation pill itself (that's Hide full screen indicator).

What causes it

HyperOS ships a runtime resource overlay, com.android.systemui.gesture.line.overlay, from /product/overlay/GestureLineOverlay.apk. It targets the android framework package at priority 2147483647 — it outranks every AOSP navigation-bar overlay on the device. Read live from a Xiaomi 13T on HyperOS 3 (Android 16, API 36):

framework resource	with overlay	without
`bool/config_imeDrawsImeNavBar`	true	false
`integer/config_navBarInteractionMode`	2	0
`dimen/navigation_bar_frame_height`	48dp	47.2dp
`dimen/navigation_bar_height`	16dp	47.2dp
`dimen/config_backGestureInset`	30dp	0dp

config_imeDrawsImeNavBar = true is the whole bug. It instructs every input method to draw its own navigation-bar row inside the keyboard window and reserve height for it. You can watch the row exist, then stop existing:

# before
mNavigationBarController={mImeDrawsImeNavBar=true
  mNavigationBarFrame=NavigationBarFrame{... 0,0-1220,144} ...}

# after
mNavigationBarController={mImeDrawsImeNavBar=false
  mNavigationBarFrame=null ...}

144 physical pixels at density 3.0 is 48dp of keyboard you were paying for and could not touch.

Why gestures still work afterwards

Xiaomi's gesture engine is not the AOSP one. It runs off global force_fsg_nav_bar and global hide_gesture_line, both independent of navigation_mode. On a fixed 13T, secure navigation_mode reads 0 — nominally 3-button — while swipes work perfectly, because MIUI's own fsgesture is handling them.

Why the settings toggle never helped

Hide full screen indicator hides the white pill. It does not touch config_imeDrawsImeNavBar, so the keyboard still builds the row and still reserves the inset. Pill gone, gap intact — which is exactly what everybody reports.

Safety

Nothing is deleted. pm uninstall --user 0 flips install state for one Android user; the APK stays byte-identical on read-only /product/overlay.
Bootloader stays locked, verifiedbootstate stays green, no partition is written.
Play Integrity / SafetyNet unaffected — no signature, property or partition change.
Reversible, tested end-to-end on a real device.

The only real cost: a factory reset or a full OTA can restore the overlay, and you run apply again.

Verified

device	rom	android	result
Xiaomi 13T	HyperOS OS3.0.5.0	16 / API 36	affected → fixed, gestures intact
POCO X3 Pro	MIUI V13.0.5.0	12 / API 31	not-affected → refused to write

The X3 Pro is the deliberate negative case: MIUI 13 has no config_imeDrawsImeNavBar at all, so the script says so instead of writing to it. Both devices were used to confirm revert restores the exact prior state.

Questions

Does this need root?

No. Plain adb shell at uid 2000. No unlocked bootloader, no Magisk, no custom recovery.

Will my banking app notice?

No. Nothing is deleted and no partition, signature or system property changes. Bootloader stays locked, verified boot stays green.

Do I lose gesture navigation?

No — but you must re-pick Gestures once in Settings, because HyperOS falls back to 3-button when the overlay disappears.

Do I need to reboot?

No. And the fix survives reboots, because per-user install state is persistent.

Do I need "USB debugging (Security settings)"?

Not on the builds tested here — plain USB debugging was enough. If your ROM refuses with a SecurityException, the script tells you to enable it. That switch needs a signed-in Xiaomi account and in some regions a 24-hour wait plus an active SIM.

Second space or work profile?

The fix is per user. Pass --user 999 (check adb shell pm list users) for the other space.

Samsung, OnePlus, Pixel?

No. This overlay is Xiaomi-specific; the script reports not-applicable and does nothing.

Check it yourself

Don't take any of this on trust — read the device:

# which overlay wins for the resource that causes the gap
adb shell cmd overlay lookup --verbose android \
  android:bool/config_imeDrawsImeNavBar

# is space being reserved at the bottom right now
adb shell dumpsys window displays | grep navigationBars

# is the keyboard drawing its own nav row
adb shell dumpsys input_method | grep -i imeDrawsNavBar

Device reports are the most useful contribution, especially HyperOS 3 builds where the verdict comes out wrong, or China / carrier ROMs that refuse the uninstall. Open a device report.