Phone test codes by brand: which secret codes still work

Before you dial anything: some codes wipe the phone

A dial code is not automatically a harmless thing. Some codes that circulate on “phone secret code” lists start a factory reset the moment you finish typing the last character — no confirmation screen, no “are you sure”, no undo. Older Samsung phones had one that did exactly that, and it is still being republished today.

They look identical to the harmless ones. Same stars, same hashes, same run of digits. You cannot tell them apart by looking, and the sites that publish them mostly copy each other rather than test anything.

So we are not printing any of them here, not even with a warning beside them — a warning is no use to someone who has already typed the code. Every code on this page opens an information screen or a test menu and changes nothing. Anything that resets, wipes, flashes firmware or alters a setting is left out.

Why so many phone test codes do nothing

Android codes in the *#*#1234#*#* shape are not really a dialler feature. Typing one makes the system broadcast a message, and something only happens if an app already on the phone has registered to listen for that exact code. If nothing is listening — because the manufacturer dropped it, or it was never on your model — the code does nothing at all. No error, no message, no feedback of any kind.

Google has narrowed that mechanism over time. The original broadcast, Telephony.Sms.Intents.SECRET_CODE_ACTION, was added in API level 28 and deprecated in API level 29 — Android 10 — with the note “it is no longer supported”. Its replacement, TelephonyManager.ACTION_SECRET_CODE, requires the sender to be the default dialler or to hold carrier privileges, and Android’s own reference describes it as something “OEM telephony apps may need to receive”. It is not a door ordinary apps can open any more.

That is why a long list of codes is not a sign of a good page. Most of the codes on those lists stopped working years ago on most phones. What matters is which codes a manufacturer still ships a listener for, and that is brand by brand, often model by model.

*#06# — the one code that works on every phone

Dial *#06# on anything, Android or iPhone, and it shows the IMEI: the number that identifies the handset itself rather than the SIM. It is the only code here that is not a manufacturer’s private addition — it is written into the mobile standard.

3GPP TS 22.030, the specification covering the dialler’s man-machine interface, defines it in clause 6.7, “Presentation of IMEI”. The wording is that the procedure shall be accepted and performed with and without an inserted SIM or USIM, and that the phone shall then display the 14 digits of the IMEI, the check digit, and optionally the software version number.

It is read-only, it works with no SIM in the phone, and it is genuinely useful: checking that a second-hand phone’s IMEI matches the box, the label under the SIM tray and the listing you bought it from.

Samsung test codes

Samsung is the brand people are usually searching for when they want a touch screen test code, and it does have a hardware test menu behind a dial code. Samsung just does not document it.

Not everything behind it is a read-out, though. The sensor and grip self-tests write calibration values rather than simply reporting a result, so they are not ones to run out of curiosity, and the speaker test plays at full volume from the moment you tap it.

• *#0*# — opens Samsung’s hardware test menu: full-screen red, green and blue fills for spotting dead pixels and discolouration, a touch test, and checks for the speaker, the earpiece, vibration and the sensors.

Xiaomi, Redmi and POCO test codes

Xiaomi documents a Settings route as well as codes, and the Settings route is the better one, because it does not depend on a listener being present for a particular code.

• Settings → About phone → tap Kernel version four times in a row. Xiaomi’s support article for the Xiaomi 14T Pro gives five taps on that model, so if four does nothing, try one more.
• *#*#64663#*#* and *#*#6484#*#* — reach the same hardware detection menu on some models. Xiaomi’s support pages mention both, with that “some models” caveat attached.

realme and Oppo test codes

realme ships a diagnostic toolkit and documents a way into it on its own community site.

• *#899# — opens realme’s after-sales page, which holds the diagnostic toolkit. Its Automatic Test runs through the LCD, the touch panel, the vibrator, the camera, the speaker, the mic, the flashlight, the headset port, the proximity and ambient light sensors, the gyroscope, the magnetic sensor, the buttons and the fingerprint scanner.

vivo test codes

We could not verify a single vivo test code, and we are not going to pretend otherwise.

The vivo codes that circulate — the engineering-mode one and the factory-test ones — appear only on aggregator sites that copy one another, with no vivo page behind any of them. At least one is described by those sites as a factory test, and that is exactly the wording that should stop you dialling something. vivo’s support site carries a long FAQ covering sensors, screens and batteries, and none of it mentions hardware test codes.

If you have a vivo phone and want to check the screen or the touch layer, the browser tests further down this page do that with nothing to dial and nothing at risk.

OnePlus test codes

There is a OnePlus code, and we are listing it rather than recommending it.

• *#808# — OnePlus only. On older OxygenOS versions this opened an engineering menu with display, touch, button, vibration and sensor tests. Do not try it, or a near-miss of it, on a Samsung: a similar-looking Galaxy code switches the USB mode, and that is one of the kinds of code this page deliberately leaves out.

Motorola test codes

Motorola has no test dial code we could verify, and does not really need one: the tests ship inside an app that is already on the phone.

Open Device Help, choose Device diagnosis, then Hardware test, and either run the full test or pick a single component. That path comes from an iFixit staff guide last updated in December 2022.

Motorola’s own support article about the Device Help app was unreachable when we checked in October 2026 — the US copy reports that the answer is no longer available, and the other regional copies were returning server errors — so we are citing the repair guide rather than a dead page.

Google Pixel test code

Google documents its diagnostics code outright, which makes this the best-sourced entry on the page.

• *#*#7287#*#* — opens the Pixel Repair Diagnostics app.

iPhone: there is no hidden test menu

This is the short section, and padding it would be dishonest. iOS has no equivalent of the Samsung or Xiaomi hardware test menu. There is no code that opens a screen, touch, speaker and sensor test on an iPhone. If a list tells you otherwise, that list is wrong.

*#06# works and shows the IMEI, as it does on every phone. Oddly, Apple’s own support article on finding the serial number or IMEI does not mention it — it lists Settings → General → About, the SIM tray, the Finder, your Apple Account on the web, and the barcode on the box. The code still works; Apple simply does not document it. We checked that article in October 2026.

*3001#12345#* opens Field Test, a cellular engineering screen with signal readings in dBm. Apple has never documented that one either, what it displays has changed between iOS releases, and threads on Apple’s own discussion forums report information disappearing from it in recent versions. It is read-only, and it only tells you about the cellular radio — nothing about the screen, the speaker or the touch layer.

For anything else, Apple’s route is Settings, or a service appointment where Apple runs diagnostics for you. There is no secret menu to find.

What we left out, and why

Far more codes were left out of this page than kept, in two groups.

The first group changes something. Factory resets. Codes that clear Wi-Fi, SIM and network settings. Codes that switch the USB mode. Codes that open a firmware-update screen for the touch layer or the camera. Codes that let you change the radio’s preferred network type. A few of those reset the phone with no confirmation at all. None of them appear here, with or without a warning, for the reason given at the top of this page.

The second group might well be harmless, but we could not stand behind them. Old AOSP-era codes for the proximity sensor, GPS, the Wi-Fi test, audio loopback and the vibration test. A monitor for Google Talk, a service that no longer exists. Several Samsung and vivo codes that appear on dozens of sites and on no manufacturer page. Some of those probably do still work on some phones. We would rather say so than print a list we have not checked.

When the code does nothing, test it in the browser

That is the common case, so it is worth having a fallback. Most of what those hidden menus check on the screen and the speakers can be checked in a browser tab instead, on any phone, with no code to dial and nothing to install.

• Touch Screen Test — drag across a full-screen grid to find dead zones and count multi-touch points. This is what people are usually after when they search for a touch screen test code.
• Dead Pixel Test — full-screen colour fills, the same job the red, green and blue screens in a manufacturer’s test menu do.
• Speaker Test — check the left and right channels and listen for rattles.
• Mic Test — record and play back to check the microphone.
• Vibration Test — check that the vibration motor still fires.

What the browser cannot test

A browser cannot reach the cellular radio, the fingerprint sensor, NFC, wireless charging or the SIM slot. For those the manufacturer’s own app is the right tool, and this page names it for each brand: Samsung Members, Device Help on Motorola, Phone Manager on realme, OnePlus Care, and the Pixel Repair Diagnostics app.