Check how much storage space your device is using right now

Your phone or computer tells you exactly how much storage is full and how much is empty. On most devices, this information lives in one settings menu, and the process takes less than a minute. The steps differ slightly between Windows, Mac, iPhone, and Android, but the principle is the same: open settings, find the storage section, and look at the bar graph showing used versus available space.

On a Windows computer, right-click the C: drive (or whichever drive you want to check) in File Explorer, select Properties, and look at the pie chart. The chart shows your total capacity and how much is currently used. On a Mac, click the Apple menu, select About This Mac, then click Storage. You will see a horizontal bar with different colors representing different types of files — photos, applications, documents, and so on.

On an iPhone, go to Settings, tap General, then tap iPhone Storage. The list shows which apps are taking up the most space, ranked from largest to smallest. On an Android phone, the path varies by manufacturer, but usually you go to Settings, then Storage or Device Care, then Storage. Look for a section labeled "Storage" or "Internal Storage" to see the breakdown.

Key Takeaways

  • Windows shows storage in File Explorer by right-clicking your drive and selecting Properties; Mac shows it in About This Mac under the Storage tab.
  • iPhone storage information appears in Settings > General > iPhone Storage, ranked by which apps use the most space.
  • Android storage location varies by phone manufacturer, but Settings > Storage or Device Care > Storage is the most common path.
  • If your device is nearly full, removing large apps, old photos, or cached files will free up space and improve performance.
  • Battery health on iPhones appears in Settings > Battery > Battery Health & Charging; most Android phones do not display this metric in settings.

Find your iPhone's battery health in Settings

iPhones show you the current condition of the battery and predict how much longer it will hold a charge. This information is in Settings > Battery > Battery Health & Charging. The screen displays a percentage — 100% means the battery is new or nearly new, while anything below 80% means the battery has degraded and may not last as long between charges.

The same menu also shows whether your phone is using Standard or Optimized Battery Charging. Optimized charging slows down the rate at which your battery ages by learning your charging habits and holding the charge at 80% until you actually need it. This setting is on by default on newer iPhones and is worth leaving enabled if you plan to keep your phone for several years.

If your battery health has dropped below 80% and your phone is still under warranty or covered by AppleCare+, you may be able to have the battery replaced at a reduced cost or for free. Outside of warranty, Apple charges a flat fee for battery replacement, which is usually less expensive than buying a new phone.

Check battery health on Android phones

Most Android phones do not display battery health in the settings menu the way iPhones do. However, you can access hidden diagnostic information by dialing a special code. On Samsung phones, open the Phone app, go to the keypad, and dial *#*#4636#*#*. This opens a hidden menu called Engineering Mode or Device Information. Tap Battery Information to see the battery's current condition and temperature.

Other Android manufacturers use different codes or do not expose this information at all. Google Pixel phones, for example, do not have a built-in battery health readout. If your Android phone does not respond to the code or you are unsure of the manufacturer, download a free third-party app from the Google Play Store that reads battery information — search for "battery health" or "battery status" and look for an app with good reviews and a large number of downloads.

Battery degradation on Android phones happens at roughly the same rate as iPhones, but manufacturers vary in how easy they make it to check. If your battery health is poor and your phone is still under warranty, contact the manufacturer's support line with your phone's serial number to ask about replacement options.

Understand what the storage numbers actually mean

When your device says you have 64 GB of storage, that number is the total capacity. The operating system itself (Windows, macOS, iOS, or Android) takes up a portion of that space — usually between 5 and 15 GB depending on the device and how many updates it has received. The remaining space is what you can actually use for apps, photos, documents, and other files.

Manufacturers sometimes advertise storage in decimal gigabytes (1 GB = 1 billion bytes), but your device measures it in binary gigabytes (1 GB = 1.074 billion bytes). This is why a 64 GB phone shows slightly less than 64 GB available — the difference is real, not a mistake. The operating system also reserves some space for system functions and temporary files, which further reduces the amount you see available.

If your device is showing less than 10% of total storage available, performance will slow down noticeably. The device needs free space to create temporary files, cache data, and perform updates. Removing large apps, deleting old photos, or clearing cached files will restore speed and stability.

Clear cached files to free up space without losing data

Cached files are temporary copies of data that apps store to load faster next time. Over time, these files accumulate and can take up several gigabytes of space. Clearing the cache does not delete your actual photos, messages, or documents — it only removes the temporary copies. On most devices, you can clear cache without losing anything important.

On Windows, open Settings, go to System > Storage > Temporary Files, and click Delete. Windows will show you how much space temporary files are using and delete them automatically. On Mac, you can use the built-in Storage Management tool (System Settings > General > Storage > Manage) or manually delete the Library/Caches folder in your home directory, though this requires showing hidden files first.

On iPhone, you cannot manually clear app cache through settings, but you can offload apps (which removes the app but keeps your data) or delete and reinstall apps to clear their cache. Go to Settings > General > iPhone Storage, tap an app, and select Offload App. On Android, go to Settings > Apps, select an app, tap Storage, and tap Clear Cache. This removes temporary files without deleting the app or your saved data within that app.

Monitor battery temperature during charging and use

Your device's battery performs best when it stays between 32°F and 95°F (0°C to 35°C). Charging in very hot environments or using your phone while it is charging can raise the temperature and degrade the battery faster. If your phone feels hot to the touch during normal use, remove any thick case, stop using power-hungry apps like video games or video recording, and move to a cooler location.

On iPhones, the Battery Health menu shows the current battery temperature. If it displays "Not Available" or shows a warning, the battery is too hot or too cold and the phone is protecting it by limiting performance. This is temporary and not permanent damage — once the battery cools down, performance returns to normal. On Android phones with Engineering Mode access, the battery temperature appears in the Battery Information menu.

Leaving your phone plugged in overnight or in a hot car for extended periods accelerates battery aging. If you plan to store a device for several months, charge it to about 50% and keep it in a cool, dry place. This slows the natural degradation that happens even when a device is not in use.

Frequently Asked Questions

What should I do if my device says storage is full?

Start by removing apps you no longer use, then delete old photos and videos (back them up to cloud storage first). Clear cached files using the steps above. If you still need more space, delete old text messages and emails, which can take up surprising amounts of storage. As a last resort, back up everything and perform a factory reset, which removes all data and reinstalls the operating system fresh.

Is 80% battery health bad, and should I replace the battery?

At 80% health, your battery still holds a useful charge but will degrade noticeably over the next year or two. If you plan to keep your phone for another two or more years, battery replacement is worth considering. If you upgrade phones every year or two, replacement is probably not necessary. Battery replacement costs vary by manufacturer but are usually between $50 and $100.

Can I trust third-party battery health apps on Android?

Most reputable battery apps (those with millions of downloads and high ratings) give accurate readings, but they cannot access the same detailed information that manufacturer diagnostic tools can. They are useful for a quick check, but if you need precise information, use the manufacturer's diagnostic code or contact support directly. Avoid apps that claim to "improve" or "extend" battery life — these typically do not work.

Why does my phone get hot when I charge it?

Charging generates heat naturally, especially on fast chargers. Some warmth is normal. If the phone is too hot to hold comfortably, remove the case, stop using the phone while charging, and move to a cooler location. Repeated overheating during charging degrades the battery faster, so if this happens regularly, try using a slower charger or charging in a cooler environment.

How often should I check my device's storage and battery?

Check storage once a month or whenever you notice your device slowing down. Check battery health on iPhones every few months if you plan to keep the phone long-term; on Android, check it once or twice a year using the diagnostic code. Neither check takes more than a minute, and both give you useful information about whether your device needs maintenance or replacement soon.