Try this before sending it in for repair or upgrade.
If your Samsung Galaxy has started draining its battery too quickly or dropping calls, or just seems to be on the wrong end of an update, there are plenty of hardware items you can check before downloading another app or heading to a repair shop.
Samsung offers a suite of phone diagnostics in Device Care. Go to Settings > Device care > Diagnostics, then tap Phone diagnostics. From here, you can test individual components or tap Test All and go through the checklist.
According to Samsung, Device Service Diagnostics are available on Galaxy devices running Android 12 or later, although the specific menus and tests available vary depending on the phone and software version. Diagnostics are also available through Samsung members.
I ran the entire test on a Samsung Galaxy S26 Ultra, which gave me 22 checks to complete. But it’s not a true measure of the “speed” of your phone. Think of it more like giving hardware a physicality.
Samsung checks a lot of your phone
Screenshot by Husain Parvez
Diagnostics go far beyond battery health. Samsung can test the touchscreen, cameras, microphones, speakers, physical buttons, sensors, Wi-Fi, mobile network, Bluetooth, SIM card, NFC, USB connection, charging and fingerprint reader, depending on your Galaxy model. Models with features such as an S Pen or wireless charging may be subject to additional controls.
Some tests are performed automatically, while others involve you. For example, the proximity test requires you to cover the area around the front camera or call speaker with your palm. Another plays audio through the call speaker and asks if you can hear it. It’s a bit more complicated than looking at a busy progress bar. If a test fails, Samsung says the app may offer troubleshooting suggestions or a related FAQ.
If you’re checking the health of an old Galaxy, the battery health is probably the most useful result. Samsung rates the battery as normal, weak, or defective. Low indicates that its effectiveness may have diminished due to long-term use or environmental conditions. Bad means battery life has degraded significantly and Samsung recommends seeking service advice.
This is much more helpful than wondering if your battery just seems worse than before.
A healthy galaxy may still seem slow
Samsung
Just because your Galaxy passes all the diagnostics doesn’t mean it will be as fast as day one. Samsung’s tests check whether components and functions work properly. They don’t give you a CPU benchmark, tell you if your internet connection is down, or tell you if your phone is performing well in games.
They are different jobs. An Internet speed test measures the connection your phone is using. Therefore, distance from the router, congestion, and other network conditions may affect the result. A benchmark like Geekbench instead measures processor performance and is more useful for comparing your phone with similar phones.
Samsung’s support guidance doesn’t specify a benchmark score at which a three-year-old Galaxy is too slow. Age alone isn’t a good indicator, as a Galaxy A-series phone and an Ultra model started with very different hardware.
If the diagnostics pass and your phone is still slow, Samsung says outdated software, background apps, insufficient available memory, or temporary system errors may be the cause. Google also says that Android phones can start experiencing issues when less than 10% of their storage is free.
Repeatedly failed diagnostic tests or a faulty battery result are good reasons to consider repairing the phone. If you hand it in for repair, Samsung’s Maintenance Mode can hide photos, messages, contacts, and other personal data while still allowing technicians to test the device.
