What Does the *#*#4636#*#* Dialer Code Do on Android? (2026)

The dialer code *#*#4636#*#* (people shorten it to 4636) opens Android’s Testing / Phone information menu on many devices. It is a leftover engineering doorway into radio and usage stats — useful for diagnostics, easy to misuse.

This guide explains what the menu contains, what is safe to touch, why some phones ignore the code, and how it relates to modern IMS/VoLTE calling.

What 4636 actually opens

On stock-ish Android builds, the code jumps straight into activities like:

• Phone information — network type, signal-ish fields, radio power, preferred network type
• Usage statistics — which apps have been in the foreground
• Wi‑Fi information — Wi‑Fi state and related counters on some builds

You usually do not press Call. On classic AOSP dialers, the menu appears as soon as the last # is typed.

What it is not

Myth	Reality
Secret “net unlock”	No — unrelated to carrier SIM locks
Battery boost code	No — mis-set modes can drain more
Proof of a fake phone	No — many real OEM phones block it
Virus scanner	No — it is a test UI

If someone sells a “4636 turbo APK,” ignore them.

Phone information fields that matter

Exact labels vary by Android version, but you often see:

• Current network / mobile radio type
• Signal strength style readouts (not always identical to the status bar)
• Phone/radio power toggle
• Preferred network type (global, LTE, NR/LTE, WCDMA, etc.)
• IMS or VoLTE-related status on some builds

IMS is how modern phones place Wi‑Fi calling and VoLTE/VoNR calls. If voice breaks after you poke radio menus, read what is the IMS service on Android before you wipe the phone.

Preferred network type: the dangerous toy

The most common self-inflicted outage looks like this:

1. User opens 4636
2. Sets Preferred Network Type to an odd GSM-only or LTE-only combo
3. Data or calls stop matching the carrier’s reality
4. User assumes the SIM is dead

Safer approach for everyday problems

• Use Settings → Network → Preferred network type / 5G toggles when available
• Prefer “automatic” / LTE/NR modes your carrier documents
• If 5G is unstable in your area, a normal Settings toggle is cleaner than engineering menus — see disable 5G on iPhone and Android

OEM dialers and blocked codes

Samsung, Xiaomi, carrier skins, and newer Android releases often do nothing when you type 4636. That is intentional hardening, not a defective unit.

On Samsung devices you may interact more with telephony UI packages than with AOSP test codes. If App info shows telephony UI names while the dialer acts strange, compare what is com.samsung.android.app.telephonyui.

Alternatives when 4636 is blocked:

• Settings → About phone → Status → SIM / network
• Carrier Settings / Service mode menus your OEM documents
• #*#*# codes that still work on that brand (varies wildly)
• Professional field test apps only from trusted sources

Usage statistics and Wi‑Fi pages

Usage statistics can help you spot a wake-lock style offender after a battery complaint, but Android’s modern Battery screens are usually clearer.

Wi‑Fi information is a quick glance at adapter state. It will not repair a bad router. For voice issues people sometimes confuse Wi‑Fi calling with cellular — check which icon you have before changing radio power.

Safe diagnostic workflow with 4636

Do

1. Screenshot the Phone information page before edits
2. Change one value at a time
3. Test calls and data after each change
4. Return to automatic network selection when finished
5. Reboot once after restoring defaults

Do not

• Turn radio power off and forget it
• Force ancient 2G-only modes “for battery” on a VoLTE-only carrier
• Follow random social posts that say “set NR only for speed”
• Pay a shop for “code programming” that is just this menu

When voice fails after menu experiments

Recovery order:

1. Preferred network → LTE/NR automatic (wording varies)
2. Airplane mode 15 seconds
3. Reboot
4. Reset network settings if still broken
5. Test another SIM if you have one

If the phone still cannot place calls and you are heading to a store, document what you changed. Use the checklist in before sending a phone for repair so a technician does not spend an hour rediscovering a preferred-network typo.

Privacy note

The Testing menu can show identifiers and radio details. Do not stream or post full screenshots publicly without redacting device identifiers. Treat it like sharing an About-phone dump.

Using 4636 while troubleshooting “No LTE” claims

Signal bars lie sometimes. Phone information can confirm whether the radio believes it is on LTE, NR, WCDMA, or something older. That helps when a friend says “you have full bars” but your phone only has edge-class speeds.

Still, treat the menu as a readout, not a tuner. If speeds are bad:

1. Confirm you are not on an ancient forced mode from last week’s experiment
2. Test another SIM
3. Move outdoors for a clean signal sample
4. Only then chase preferred-network myths from social media

Dual-SIM complications

On dual-SIM phones, voice and data may live on different slots. The Testing menu may show the active data SIM’s radio story while your call SIM is the one failing. Switch default call/data SIMs in normal Settings rather than hunting undocumented 4636 toggles for SIM2.

After carrier settings or OS updates

Carrier config packages can reset network behavior. If 4636 tinkering coincided with an update, restore automatic modes and reboot twice before assuming the modem failed. Write down the preferred network value you started with — future you will want that string.

Related FixingHacks guides

• What is the IMS service on Android
• Disable 5G on iPhone and Android
• What is com.samsung.android.app.telephonyui
• Before sending a phone for repair

Bottom line

*#*#4636#*#* opens Android’s engineering Testing / Phone information menu on supported dialers. Use it to read network state; be extremely careful changing preferred network type or radio power. Many OEM phones block the code entirely — that is normal. If calls break after you experiment, revert to automatic modes, reset network settings, and document everything before repair.