How do I run an adb shell command?

Switch on developer options and USB debugging on the phone, plug it in, then run adb shell from a machine with platform-tools installed — or run adb shell on its own to get an interactive prompt and type the command without the prefix. If the command produces binary output, such as a screenshot, use adb exec-out instead of adb shell: the plain shell service attaches a terminal, which rewrites newline bytes and corrupts the data.

Do adb shell commands need root?

Not the ones on this reference. They run as the shell user, which can manage packages for its own Android user, read most dumpsys services, write the settings provider, inject input and read shared storage. Root is only needed for things this reference deliberately avoids — reading another app's private data (except through run-as on a debuggable build), writing system partitions, or reading /data/anr directly.

Why does the output look different on my phone?

Either the Android version or the manufacturer. Some flags and fields arrived in a specific release, and those are noted per command. The rest is OEM patching, which hits dumpsys hardest: a dump is debug output whose text is whatever the service author last printed, and manufacturers change it and backport their changes. Read fields by name rather than by position, and treat an unfamiliar shape as a difference rather than as a failure.

Can I run this from a browser instead of a terminal?

For many commands, yes — the Web ADB tools on this site talk to a phone over WebUSB from a Chromium-based desktop browser, with no SDK installed and nothing uploaded. Each page links to the tool that runs its command, when one exists. Two limits are worth knowing: only one program can hold the ADB interface at a time, so a desktop adb server has to be stopped first, and adb forward and adb reverse cannot work in a browser at all.

settings put

changes the device

Writes a value into the settings provider — the mechanism behind most developer-options tricks.

Command: adb shell settings put
Commands: Settings provider
Risk: changes the device

Syntax

settings put <system|secure|global> <key> <value>

Flags and arguments

Token	Meaning
system \| secure \| global	The namespace. Writing a key into the wrong one creates a key nothing reads, and it fails silently.

Examples

```
settings put global window_animation_scale 0.0
```
Turn one animation off. Developer options actually sets three scales; `transition_animation_scale` and `animator_duration_scale` are the other two.
```
settings put system show_touches 1
```
Draw a dot where the screen is touched — useful for recording a demo.
```
settings put global http_proxy 10.0.0.5:8080
```
Point the phone's HTTP stack at a proxy on your machine.
```
settings put global http_proxy :0
```
Clear the proxy. `:0` is what the platform's own settings UI writes.

Reading the output

Nothing on success. Silence is the answer, so verify with `settings get` rather than believing the absence of output — a write into the wrong namespace is just as silent as a correct one.

Output fields

Field	Meaning
(no output)	The write was accepted.
Exception / Permission Denial	The shell user may not write that key on this build.

What access it needs

No root and no `adb root`, but this is the half of the family that leans on a real platform permission. `settings` is a one-line shell script running `cmd settings "$@"` (AOSP `cmds/settings/settings.sh`), so the write is attempted as the `shell` user, and `com.android.shell` — the package that user runs as — is granted both `android.permission.WRITE_SETTINGS` and `android.permission.WRITE_SECURE_SETTINGS` in its own manifest. That is why an authorised cable can change `secure` and `global` keys no ordinary app may touch, and why nothing in developer options gates it beyond USB debugging itself. What the grant does not give you is a guarantee per key: an individual key can still be refused by the provider, and a refusal arrives as an exception banner with a stack trace under it rather than as a tidy one-line error. Then there is the stream question, which matters more here than anywhere else on this site, because a successful write prints nothing at all. Values go to stdout, parser complaints go to stderr, and silence is the success signal — so "it worked", "it was rejected and you threw the rejection away" and "it wrote into a namespace nothing reads" are the same observation unless you keep stderr and read the key back afterwards.

Failure messages, decoded

Message	Meaning
Bad arguments	The command line ended before a complete request existed. For `put` that means the value is missing: `settings put global http_proxy` alone lands here. Nothing was written, and nothing names which piece was short, so check the whole line.
Too many arguments	`put` accepts a namespace, a key, a value, an optional tag and then only the literal word `default`; anything beyond that is refused. The trap is one word short of this error: an unquoted value with a single space in it does not fail, it writes the first word as the value and silently takes the second as the tag. Quote the value, then read it back.
Argument expected to be 'default'	Five positional arguments were supplied and the fifth was something else. The parser only allows `default` in that position, which is the switch that also makes the value the new platform default. Nothing was written.
Exception occurred while executing 'put':	The shell-command handler caught a `Throwable` and wrote this banner plus the stack trace to stderr. The line after it names the cause: a `java.lang.SecurityException` means the provider refused that particular key, not that the value was malformed. You only see any of it if you kept stderr, and the write did not happen.
Invalid namespace 'gobal'	The namespace has to be `system`, `secure` or `global`, matched case-insensitively. Parsing stops immediately, so nothing was written — which is the good outcome, because the alternative is a key sitting in a table nothing reads.

What it changes, and the way back

There is no derivable antidote: the platform does not remember what the value was, so read it with `settings get` *before* you write and keep that number. The proxy key is the one that bites hardest — a phone that leaves the building with `global http_proxy` set has no working internet on any network and nothing on the phone explains why. Clear it with `settings put global http_proxy :0`, not with an empty string.

Version and vendor notes

Restoring means writing the old value back, which means having read it first. The command has no undo of its own.
Clearing the proxy with an empty string does not work reliably: several builds store the two quote characters literally and leave the phone pointed at nothing useful. `:0` is the value to write.
"Animations off" is three keys, not one. Setting only the window scale leaves transitions and animators running.

We have a UI for this

Android ADB Toolbox runs this command over USB and parses what comes back — a Chromium browser, no SDK, nothing uploaded.

Open Android ADB Toolbox

Related commands

Commands that turn up in the same session as settings put.

Command	What it does
settings get	Reads one value out of the phone's settings provider.
am broadcast	Sends a broadcast intent, which is how SystemUI demo mode and other platform receivers are driven from a shell.
wm size	Reports the display's resolution, or overrides it so the phone pretends to be a different screen.

Checked against AOSP, toybox and kernel sources while writing the parsers behind our Web ADB tools. Where a behaviour genuinely varies by Android version or manufacturer, this page says so instead of giving a number that would be wrong on half the phones out there.