Android debloat & speed over adb (no root)

Works on any Android 9+ phone with USB debugging. Verify on the actual device every time, vendor behavior differs (Sony, Samsung, Xiaomi remove features silently).

Diagnose before touching anything

Run all four; each maps to a distinct root cause:

adb devices -l                                        # must say "device", not "unauthorized"
adb shell df -h /storage/emulated | tail -1           # >90% full → Android itself degrades
adb shell top -b -n 1 | head -8                       # kswapd0 high CPU = RAM starvation (THE hidden killer)
adb shell dumpsys meminfo | grep -E "Free RAM|ZRAM"   # big ZRAM/swapped = swap tax on every app switch
adb shell dumpsys alarm | grep -B1 -A3 wakeups        # who wakes the CPU (battery + lag)

Leading insight: kswapd burning CPU means RAM starvation, not CPU weakness. Fix = uninstall big unused apps + reboot (clears swap). No amount of "cleaner" apps helps.

Safe-action ladder (most reversible first)

1. adb shell pm trim-caches 512G purges all app caches instantly
2. adb shell pm disable-user --user 0 <pkg> reversible bloat kill (pm enable <pkg> reverts). Prefer over uninstall.
3. adb shell pm uninstall --user 0 <pkg> user apps the user names explicitly (Play Store reinstallable)
4. adb shell settings put global window_animation_scale 0.5 (+ transition_animation_scale, animator_duration_scale) visible snappiness, 1.0 reverts
5. NEVER pm uninstall system-critical pkgs (SystemUI, phone, providers). If UAD says Unsafe/Expert, skip.

Debloat database

Pull UAD-ng lists: raw.githubusercontent.com/.../main/resources/assets/uad_lists.json (5k+ pkgs, removal: Recommended/Advanced/Expert/Unsafe). Cross-reference with adb shell pm list packages -s, then apply user-context overrides: keep aptX/BT codecs if BT headphones, keep SIM/uim on modem-dependent devices, keep anything the user's apps depend on. Recommended ≠ always safe for THIS user.

Log every change to a file on the phone (/data/local/tmp/debloat.log), the rollback ledger.

Bulk file moves to microSD (the slow path that works)

microSD over adb is ~2–4 MB/s (FUSE + exFAT). Never block an interactive session:

1. Push a shell script to /data/local/tmp/, run detached: adb shell 'nohup sh script.sh >/dev/null 2>&1 &'
2. Script does per-item: cp -a → compare file count AND byte totals → delete source only on exact match → append verdict to a log
3. Poll the log from the host. No reboot while it runs (kills the job).
4. MTP won't show adb-copied files in Music/DCIM/Pictures (different uid); the files are fine; check with an on-device file manager.

Hard limits (verify per device, don't assume): WhatsApp media and app cannot move to SD (hardcoded + vendor killed adoptable storage on Android 9+). Google Maps offline areas CAN move: in-app → Offline maps → ⚙ → Storage preferences → SD card (requires re-download).

Known traps

• Phone toybox sort lacks -h → use du -k + sort -rn
• dumpsys diskstats size arrays are positional, never map indexes to package names (mis-blames apps); use du -k -d 1 /storage/emulated/0/Android/media and Android/data instead
• pm clear frees ~0 when the bloat lives in Android/media (shared storage), not app-private /data/data
• ps -A | grep cp may miss busybox cp; use pidof cp
• Syncthing .stfolder markers = active sync, check sync direction before deleting on either side
• Vendor telemetry (Sony devicemonitor/crashmonitor, FB services) can fire 1k–7k alarms/day; disabling them is the cheapest battery+CPU win

Per-phone state

Device-specific ledgers (what was changed, rollback list, storage map) live in per-project docs. Check for a similar dir before re-diagnosing a phone already worked on.