6 hidden Samsung dial codes that unlock secret features on your Galaxy phone

That dialpad on your Samsung Galaxy phone isn’t just for making calls. Type the right combination of numbers, asterisks, and symbols into it, and you’ll unlock menus and features you had no idea existed.

These are MMI (Man-Machine Interface) codes, and with them, you can pull up your device’s IMEI, hide your caller ID, clear old system logs, test almost every piece of hardware on your phone, and do a lot more.

Most Galaxy users have no idea any of this exists. After reading this article, you will.

Most Samsung dial codes won’t work until you change this setting

Things used to be much simpler back in the day. You’d open the dialer, punch in a code, and it just worked. But that’s not quite the case anymore, at least not for all the MMI codes. So before you start entering them, you need to turn off One UI’s Auto Blocker feature. It’s a security feature that blocks sideloading, USB commands, malicious activity, and non-official software updates. As a side effect, it also stops most dial codes from working.

To turn it off, head to Settings > Security and privacy and turn off Auto Blocker. The good thing is that you don’t have to remember to turn it back on if you’re running One UI 8.5 or later — your Galaxy phone will automatically re-enable it after 30 minutes.

One more thing. If you’re using a carrier-locked Galaxy phone, some codes may throw a “connection problem” error even with Auto Blocker disabled. That’s the carrier restricting access rather than Samsung — and sadly, there’s not much you can do about it. For context, I tested all the following codes on an unlocked Galaxy S26, and they worked without any issues.

Find your IMEI instantly: *#06#

The IMEI (International Mobile Equipment Identity) is your phone’s unique 15-digit identifier. If your Samsung phone ever gets lost or stolen, this is the number your carrier will ask for to block the device from connecting to any network. It’s also what you’ll need when filing an insurance claim or reporting the theft to the police. If you have a dual-SIM Galaxy phone, dialing *#06# will show you two different IMEI numbers.

Of course, this isn’t the only way to find your phone’s IMEI. It’s also printed on the box and buried in the About Phone menu. However, using the dialer is by far the quickest method.

Hide caller ID: *67 or *31#

If you ever need to call someone without revealing your number, dialing *67 before a phone number — for example, *67-123-456-7890 — is the way to go. If you’re outside the US, dial *31#, and the caller ID will be hidden for all outgoing calls. This will make your phone number appear as “Unknown” or “Private Number” on the recipient’s phone.

Since this works over your mobile network, whether it’s effective or not, depends on your carrier and region. Some carriers may ignore the suppression request entirely and still show the number anyway.

Change USB connection modes: *#0808#

Every time you connect your Galaxy phone to a PC, Android picks a USB mode for you. Usually, it’s Charging only, but you can easily change that from the Android System notification that appears when you connect. And if you want that change to stick, you need to unlock the Developer Option menu and set a different default USB mode.

But if you don’t want to go that route, dialing *#0808# is a good alternative. This opens the USB Settings menu, which shows every USB mode your device supports. By default, it’s set to Charging, but you can switch to MTP (Media Transfer Protocol) if you regularly transfer files to a computer. You’ll see a third option named RNDIS + ACM + DM. RNDIS is for USB tethering, while ACM and DM are mainly for diagnostics and firmware flashing.

Update touchscreen firmware and refresh Wi-Fi version: *#2663#

If your Galaxy’s touchscreen feels slightly off, *#2663# is worth trying before going down the troubleshooting rabbit hole. Dialing this opens a firmware update menu where you’ll see the TSP FW UPDATE button. TSP stands for Touch Screen panel, which is essentially the layer that detects and processes touch input.

In the same menu, you’ll see a Refresh Wi-Fi Version button. As you might guess from its name, this option can be handy if you’re having Wi-Fi connectivity issues. Tapping this option will reboot your phone, so don’t be surprised when that happens.

Delete old system logs: *#9900#

Your Galaxy phone logs all kinds of system activity in the background, including app crashes, system errors, and other diagnostic information. Most of these logs are only useful for troubleshooting and, over time, can consume valuable storage space.

To reclaim that storage, dial *#9900# and you’ll see the SysDump menu. Tap Delete dumpstat/logcat, and your phone will remove all the accumulated log files. In my case, it freed up 1.2GB of storage space in the “Other files” category.

Run a complete hardware diagnostic: *#0*#

I saved my favorite dialer code for last. Dialing *#0*# opens a hardware diagnostics menu on your Galaxy phone. It’ll show a grid of tests that let you check almost every major hardware component on your phone.

Most of the tests are pretty self-explanatory. The Speaker option, for instance, plays audio through different speakers on your phone so you can test them individually. The Touch option lets you draw across the screen to detect unresponsive or dead zones. Vibration fires the haptic motor, while the Sensors tab shows live readings from the accelerometer, gyroscope, proximity sensor, and several other sensors.

A couple of things to note here. Some tests will run automatically when you tap them, while others will require you to interact with them. And to exit any test, you’ll have to use the back gesture multiple times or press the volume keys. Either way, it’s not too difficult to figure out.

So that’s my list. Of course, there are plenty of other dial codes that work on Galaxy phones, but I wanted to focus on the ones that are genuinely useful.

Do you know any other dialer codes that you find useful? Tell us about it in the comments below.