When mobile data stops working on Android, the most useful clue is what still works. A phone with no signal, a phone with full bars but no internet, and a phone where only one app fails are three different problems.
Before resetting anything, identify which situation matches your phone.
Start With These Four Checks
Turn WiFi off so you know you are testing cellular data.
Then check:
- Do you have signal bars?
- Can you make a normal phone call?
- Can you send or receive an SMS?
- Does any app or website work on mobile data?
Those answers narrow the problem quickly.
No signal or “No service”
Focus on:
- carrier coverage;
- SIM or eSIM activation;
- network registration;
- carrier outage;
- hardware.
Signal bars are present but nothing loads
Focus on:
- active data plan;
- correct SIM for data;
- APN;
- roaming;
- carrier outage;
- mobile network settings.
Only one app fails
The mobile connection is probably working.
Check that app’s:
- mobile-data permission;
- background-data setting;
- Data Saver access;
- account or service status.
Calls and texts work but mobile internet does not
This strongly points toward:
- the data plan;
- APN settings;
- mobile-data provisioning;
- the selected SIM;
- a carrier-side data problem.
Do not start with a factory reset.
Confirm Mobile Data Is Actually Enabled
On Pixel and many Android phones:
Settings > Network & internet > SIMs > [SIM] > Mobile data
On Samsung Galaxy:
Settings > Connections > Data usage > Mobile data
You can also use the Mobile data tile in Quick Settings.
If you use two SIMs, confirm the correct one is selected for mobile data.
A dual-SIM phone can have working calls on one line while trying to use another line for internet access.
If Android is not detecting the SIM properly, use SIM Card Not Detected on Android before changing APN settings.
Check Your Data Plan Before Changing Settings
A mobile-data switch can be on even when the carrier is not allowing internet access.
Check your carrier account or app for:
- exhausted data allowance;
- expired bundle;
- suspended service;
- unpaid balance;
- roaming restriction;
- line activation problems.
If calls and SMS still work but no website loads, this check can save a lot of unnecessary troubleshooting.
Also test another website or app.
One broken service does not prove mobile data is down.
Look at the Status Bar
The status bar can reveal where the problem is.
No bars or emergency calls only
The phone is not registered normally on the carrier network.
Move to an area with better coverage and toggle Airplane mode once.
If the problem continues everywhere, investigate the SIM, eSIM, carrier, or device.
Bars but no 4G, LTE, 5G, or mobile-data indicator
Mobile data may be disabled, unprovisioned, or using the wrong SIM.
4G/LTE/5G appears but nothing loads
The phone is attached to a data network, but internet traffic is still failing.
Check the carrier plan, outage status, APN, VPN, Private DNS, and network settings.
Strong signal bars do not guarantee working internet.
Refresh the Cellular Connection
Before editing network settings:
- Turn Mobile data off.
- Turn Airplane mode on.
- Wait about 10 seconds.
- Turn Airplane mode off.
- Wait for the carrier name and data indicator to return.
- Turn Mobile data on if necessary.
- Test again.
This forces the phone to register with the network again.
A normal restart is also worth trying if the problem started suddenly.
These steps are safer than immediately resetting all network settings.
Check the Correct SIM on Dual-SIM Phones
Open the phone’s SIM settings.
On Pixel:
Settings > Network & internet > SIMs
On Samsung:
Settings > Connections > SIM manager
Confirm which SIM is assigned to Mobile data.
If you recently:
- added an eSIM;
- moved a physical SIM;
- traveled;
- changed carriers;
- transferred to a new phone;
Android may be using a different line from the one you expect.
On some dual-SIM phones, only one line can be the preferred data SIM at a time.
If You Use an eSIM
An eSIM can appear in Settings even when carrier activation is incomplete.
Check that:
- the eSIM is enabled;
- the correct eSIM is selected for data;
- your carrier finished activation;
- the plan is active.
On Pixel, Google currently places eSIM controls under:
Settings > Network & internet > SIMs
If activation or transfer repeatedly fails, contact the carrier.
Deleting an eSIM profile should not be an early troubleshooting step because you may need carrier assistance or a new activation code to restore it.
Check Whether Data Roaming Is Required
When you are outside your carrier’s normal network, mobile internet may require Data roaming.
On many Android phones:
Settings > Network & internet > SIMs > [SIM] > Roaming
On Samsung:
Settings > Connections > Mobile networks > Data roaming
Only enable it if your carrier plan supports roaming and you understand the charges.
If calls work abroad but internet does not, roaming settings and carrier roaming support are more likely causes than an Android software fault.
Check the Preferred Network Type
Android normally chooses the appropriate available network automatically.
On Pixel:
Settings > Network & internet > SIMs > Preferred network type
Samsung commonly uses:
Settings > Connections > Mobile networks > Network mode
Use the normal automatic option provided by your carrier.
Do not force 2G or an unsupported network type because an old troubleshooting guide recommends it.
If 5G is unstable in one location, testing LTE/4G temporarily can help determine whether the problem is specific to the local 5G connection.
If you intentionally want to disable 5G, see How to Turn Off 5G on Android.
Reset the APN to Carrier Defaults
The Access Point Name, or APN, tells Android how to connect to the carrier’s data service.
A wrong APN can produce a classic symptom:
calls and texts work, but mobile data does not.
On Samsung:
Settings > Connections > Mobile networks > Access Point Names
Samsung currently recommends using Reset to default when incorrect APN settings are suspected.
Other Android phones usually place APN controls under the selected SIM or Mobile network settings.
Before manually typing values from a random website:
- Use Reset to default if available.
- Restart the phone.
- Test mobile data.
- If it still fails, get the APN details from your carrier’s official support.
Do not invent APN values.
The correct settings vary by carrier and plan.
Check Data Saver and Per-App Data Restrictions
If Chrome works on mobile data but another app does not, do not reset the entire network.
Open:
Settings > Apps > [app]
Look for a menu such as:
- Mobile data & WiFi;
- Mobile data;
- Data usage.
Make sure the app is allowed to use mobile data.
Also check:
Settings > Network & internet > Data Saver
or the equivalent Samsung menu.
Data Saver usually does not disable all mobile internet. It mainly restricts background data for apps that are not exempt.
This distinction matters.
If notifications arrive only when you open an app, see Android Notifications Not Working because background-data restrictions may be the real issue.
Temporarily Disable VPN and Custom Private DNS
A broken VPN connection or custom DNS configuration can make mobile data look completely dead.
Temporarily disconnect any VPN.
If you changed Private DNS manually, switch it back to Automatic for a test.
Then try:
- a browser;
- Google Play;
- another internet-dependent app.
If everything starts working, the cellular connection was not the problem.
Reconfigure or remove the VPN/DNS service that was blocking traffic.
Check for a Carrier Outage
If several people using the same carrier in your area suddenly lose data, changing Android settings is unlikely to help.
Check:
- your carrier’s official status page or app;
- carrier support;
- reports from another device;
- whether calls and SMS are also affected.
During an outage, repeated resets can leave you with extra settings to restore after the network comes back.
Mobile Data Stopped Working After an Android Update
Do not assume the update permanently damaged the phone.
First:
- Restart the phone.
- Toggle Airplane mode.
- Confirm the correct SIM is selected.
- Check for another system update.
- Update carrier-related system components and the Phone app where applicable.
- Reset the APN to default.
- Test again.
If multiple apps also started crashing after the same update, see Apps Keep Crashing After Android Update.
A post-update mobile-data problem that survives APN and network checks may need carrier reprovisioning rather than more Android cleanup.
Test the SIM in Another Phone When Practical
A cross-test is one of the strongest diagnostics for a physical SIM.
Put the SIM into a compatible unlocked phone.
Mobile data works there
The account and SIM are probably okay.
Focus on the original phone’s:
- network settings;
- software;
- SIM reader;
- carrier compatibility.
Mobile data also fails there
Focus on:
- carrier service;
- data plan;
- SIM provisioning;
- damaged or outdated SIM.
Do not perform this test with an eSIM by deleting and transferring profiles casually.
For eSIM problems, carrier verification is safer.
Reset Mobile Network Settings Last
Use a network reset after the targeted checks above have failed.
Pixel currently provides:
Settings > System > Reset options > Reset mobile network settings
Samsung currently provides:
Settings > General management > Reset > Reset mobile network settings
A mobile-network reset does not delete your photos or apps.
But menu behavior differs by device, and some broader network resets may also remove saved WiFi or Bluetooth settings.
Samsung also warns that customized APN information may need to be entered again afterward.
That is why I would not use reset as the first fix.
After the reset:
- Restart if prompted.
- Wait for the phone to register on the carrier network.
- Confirm the correct SIM is selected.
- Test mobile data before changing anything else.
Mobile Data Works but Hotspot Has No Internet
That is a separate problem.
If websites load normally on the Android phone but devices connected to its hotspot cannot reach the internet, the cellular-data connection itself is working.
The problem may involve:
- hotspot allowance;
- tethering restrictions;
- hotspot settings;
- receiving-device compatibility.
Use Android Hotspot Not Working instead of repeatedly changing the phone’s APN.
WiFi Works but Mobile Data Does Not
This tells you something useful.
The phone’s browser, apps, and general internet capability are probably fine.
Focus on the cellular side:
- correct SIM;
- active plan;
- signal;
- APN;
- roaming;
- carrier;
- mobile network settings.
If the opposite happens and WiFi connects without internet, use Wi-Fi Connected but No Internet on Android.
Keeping those problems separate avoids changing unrelated settings.
When to Contact Your Carrier
Contact the carrier when:
- your plan is active but no mobile data works;
- APN reset does not help;
- the SIM fails in another compatible phone;
- an eSIM will not activate;
- the phone shows service but data never connects;
- the problem began after a SIM/eSIM transfer;
- mobile data works only intermittently in places with normally good coverage.
Ask them to check:
- account provisioning;
- mobile-data provisioning;
- SIM/eSIM status;
- outages;
- device compatibility;
- APN requirements.
A carrier can fix provisioning problems that no Android setting can repair.
When the Phone Itself May Be the Problem
Phone hardware becomes more plausible when:
- several known-good SIMs fail in the same phone;
- the phone repeatedly loses all network registration;
- the SIM is frequently detected and then disappears;
- the problem began after physical or liquid damage;
- other radio functions also behave abnormally.
Before paying for repair, test another compatible SIM and confirm there is no carrier outage.
If the phone cannot recognize the SIM consistently, return to SIM Card Not Detected on Android for the hardware-versus-SIM checks.
