When every SmartThings device goes unavailable at once, the issue is usually the app, Samsung account sync, the hub, internet access, or a SmartThings cloud outage. It is rarely every individual bulb, plug, lock, and sensor failing at the same time.
These steps apply to the SmartThings app on iPhone and Android, with either a physical Samsung SmartThings hub or a hub-less cloud-connected setup.
Does this affect you?
Use this if SmartThings will not open, hangs on the loading screen, crashes, or shows multiple devices unreachable even though those devices still have power.
Check for a SmartThings service outage first
SmartThings depends on Samsung cloud services for many app functions. If those servers are down, local troubleshooting will not bring the app back immediately.
- Open a browser on your phone or computer.
- Check the Samsung SmartThings status page.
- Search for recent reports such as SmartThings down if the status page is unclear.
- If an outage is listed, wait and check again later.
- If no outage is reported, continue with the app checks below.
Most cloud outages clear within a few hours. During that time, automations and app control may be inconsistent even if your home Wi-Fi is working.
Clear the app cache and force-restart it
This is the fastest fix for crashes, frozen screens, and stale device status.
- On Android, open Settings > Apps > SmartThings > Storage and tap Clear Cache. Avoid Clear Data unless you are ready to sign in again.
- On iPhone, open the app switcher and swipe SmartThings away completely, then reopen it.
- Restart the phone, not just the app, so stuck background processes are cleared.
- Open SmartThings again and wait a minute for device status to refresh.
Sign out and back into your Samsung account
Use this when the app opens but locations or devices do not load correctly.
- Tap your profile icon in SmartThings.
- Scroll down and choose Sign Out.
- Close the app fully.
- Open SmartThings and sign in again.
- Wait while the app resyncs your home, rooms, devices, and automations.
- Confirm you are using the same Samsung account that originally owns the location.
A second Samsung account, even one used by a family member in the same house, may not show your devices unless it was invited to the SmartThings location.
If you have a physical SmartThings hub, check its light. A normal online light is usually solid green or blue, depending on model. If it is off, blinking red, or otherwise abnormal, unplug the hub for 30 seconds, plug it back in, and give it time to reconnect.
SmartThings also needs a working internet connection. Test another device on the same network before reinstalling anything. If the app still fails after cache clearing and sign-in, delete SmartThings and reinstall it from the App Store or Google Play. Your devices are tied to the cloud account, not only to the app install.
If SmartThings works on another phone but not yours, or the same account stays broken for several hours, contact Samsung SmartThings support from Settings > Support so they can check the account and location from their side.
Sources
- Samsung SmartThings Support – App Troubleshooting (2025)
- Samsung SmartThings Support – Hub Not Responding (2025)
- Samsung SmartThings Status Page – Service Outages (2025)