It should come as no surprise that tech companies use the location services on your smartphone to track your comings and goings.

That’s how they give you up-to-date traffic reports, restaurant recommendations, and other helpful information. But they also sell that information to marketers and other companies interested in studying your habits.

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While this isn’t exactly breaking news, the extent of the info collection might unsettle you. According to the media website Quartz, which recently dissected location data sent from three different Android phones back to the Google mother ship, it includes the local barometric pressure, the charge level of your battery, and the address and signal strength of every nearby WiFi access point.

To some people, that may seem like too much. But cutting off, or at least cutting down, the amount of location data that Google and other companies collect is easier than you think. 

Here’s how to do that.

Android Phones

To its credit, Google does ask you to opt in to location services tracking before it starts to monitor your travels. But you may well have agreed to the idea without thinking about it. Requests for consent usually arrive in those pop-up notifications that people accede to in order to get on with their day.

If you want to go back and manage your location history, Google provides instructions for that. But here, in a nutshell, is what you need to do:

Go to Settings > Google > Location

At the top of the screen you’ll find a toggle switch that allows you to turn off all location access. But if you’d prefer to let certain apps track you, leave that switch in the On position and scroll down to App-Level Permissions.

From there, you can manage the access for individual apps. You may say “yes” to Google Maps, for example, but “no” to apps for retailers and video games. Note that Google itself gets location data from phones that have location history enabled, even when you’re using an app such as Facebook or Yelp. 

If you’re curious to know which apps have recently requested your GPS coordinates, you can see a short list on the main Location screen.

You can also choose whether to give Google access to your location history on each of the devices tied to your Google account. To do this, scroll further down the Location page until you find the list of accounts under Location Services. Select one, then use the toggle switches on the following page to manage the access device by device.

Apple Phones

Apple makes a big point of saying it doesn’t sell user information to outside companies, but the same can’t be said for the companies that make the apps you install on your iPhone.

Like Google, Apple provides instructions on how to manage your location data

In short, go to Settings > Privacy > Location Services

At the top of the screen, there’s a toggle switch to turn the tracking off completely. And below that you’ll find the list of apps that use location services. Tap on one and you can decide for yourself whether to grant it access “always,” “never,” or only “while [you’re] using the app.”

Different choices will give you different functionality. For example, allowing Google Maps full access will get you real-time traffic and transit updates in addition to basic maps and directions.

You can also use the Location Services page to see which apps have recently received your location. That’s indicated by arrows.

Beneath the list of apps is an option called System Services. Selecting that will give you a list of situations when your iPhone might want to access your location, such as when it’s looking for a cell-phone network or wants to send an emergency SOS, track how far you walk for fitness purposes, or send you ads based on where you are.

Use the toggle switch for each to manage access as you please. You can also block the location data collection Apple uses to improve its maps app, traffic and route information, and other features.