While location-tracking data is often anonymized before being sold on, it can reveal an alarming amount of information about your activity. It’s not just about where you shop — it shows everywhere you go, which may include anything from a prenatal clinic visit to an AA meeting, revealing potentially sensitive details about your life.

If you’re concerned about your privacy, or just kind of creeped out, you can take action to prevent apps from tracking your location. Here’s how to prevent app location tracking on Android or iOS.

FIND OUT WHICH APPS HAVE LOCATION DATA ACCESS

It’s a very good idea to start with a review of the apps on your phone that have access to location data. There are legitimate reasons for many apps to track your location, so be aware that denying access to location tracking may prevent some apps from working properly. A navigation app like Google Maps, for example, is not going to be anywhere near as useful if it doesn’t know where you are.

HOW TO PREVENT LOCATION TRACKING ON AN ANDROID PHONE

If you have an Android device, and you want to turn off location tracking entirely, then it’s easy to do, although the precise instructions will differ slightly from phone to phone.

On a Google Pixel 3, go to Settings > Security & location > Location and toggle Use location off.

On a Samsung Galaxy S9 Plus, go to Settings > Connections > Location and toggle it off.

On a Huawei P20 Pro, go to Settings > Security & privacy > Location services and toggle off Access to my location.

This will turn off all location tracking, so no apps will be able to access your location. It also means that, in theory, Google won’t track or save your location, though there’s evidence it will anyway. You may also still get ads based on your IP address location.

Unfortunately, turning off location altogether also means that you can’t track your phone if it goes missing, you can’t see or share your location in Google Maps, and some other services and apps may not work as well as they otherwise would.

Another setting worth looking at if you want to limit Google’s tracking is your Web & App Activity. You can find full instructions on how to control and delete searches and browsing activity, which sometimes also includes location, from Google.

HOW TO JUST RESTRICT SPECIFIC APPS IN ANDROID

If you decide that turning off location tracking altogether is a step too far, you can still toggle off specific apps that you’d prefer not to have location access. Once again, the instructions will vary a little depending on your phone.

For example, on a Pixel, go to Settings > Apps & notifications > Advanced > App permissions > Location.

On a Samsung Galaxy, it’s Settings > Apps > Menu (three dots at top right) > App permissions > Location.

On a Huawei phone, it’s Settings > Apps & notifications > Permissions > Your location.

Review the list and toggle off anything that you’d prefer did not have the ability to track your location.

HOW TO PREVENT LOCATION TRACKING ON AN IPHONE

Things are a little more straightforward with iOS, so if you want to turn off location tracking on your iPhone, or just restrict certain apps, then you need to go to Settings > Privacy > Location Services, where you can choose to toggle Location Services off completely.

Bear in mind that this will impact some services and apps, such as Maps and Find My iPhone, so it might be a step too far. Although, it’s worth noting that Location Services can be re-enabled on the device if it’s in Lost Mode. You can put your iPhone into Lost Mode via iCloud.

In Settings > Privacy > Location Services, you’ll also see a list of apps that have location data access and you can tap on each one and decide whether it should be allowed to access your location Never, While Using the App, or Always.

WHAT ABOUT THE LOCATION DATA ALREADY RECORDED?

Now that you’ve prevented various apps and services from tracking your location going forward, you may be wondering whether you can delete the location data that companies have already collected about your movements.

If you have an Android phone, then you can ask Google to delete your location history. Simply follow that link, make sure you’re signed into your Google account, and tap the red Delete Location History button. Bear in mind that it will delete the information permanently and you won’t be able to get it back.

If you have an iPhone, then go to Settings > Privacy > Location Services and scroll down to find System Services > Significant Locations, then tap Clear History at the bottom. Apple claims this information is encrypted and can’t be read by Apple, so this may be unnecessary.

As for the location data collected by other companies through the apps you’ve been using, there’s no easy way to find out what it is or to delete it. You could start by referring to the organization in question’s privacy policy and get in touch with them, but it’s very possible they’ve already sold your data and they don’t have any legal duty to help you in the U.S.

If you’re in the European Union, you do have a legal right to request a copy of the data that a company has collected on you, including location data, and to insist that they delete it. Check out the U.K. Information Commissioner’s Office guide for details on your rights and how to request data, but be prepared to jump through some hoops.

To further safeguard your privacy, we recommend using one of the best Android VPN apps or the best iPhone VPN apps.