If you're a regular Steam player, you might want to inject some of your personality into your public profile. A good way to do this is to change your Steam profile picture to a custom avatar.

You can change your profile picture on Steam using the desktop application or via the company's website. The steps for both methods are the same, so you should be able to follow these steps using either the client or the website.
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To get started, open the Steam client on your Windows 10 PC or Mac , or visit the Steam website and log in to your account. Once logged in, select your account username in the top right corner and select “View Profile” from the drop-down menu.

In the menu for your account, click “Edit Profile”.

Select “Avatar” in your Steam account profile settings to change your profile picture.

In the “Avatar” menu, click the “Upload Your Avatar” button to upload a new profile picture. This image must be at least 184 pixels x 184 pixels in size.
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Alternatively, select one of the profile images provided by Steam below. To see the full range of Steam avatars, click the “See All” button.

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You will be able to preview your new profile picture at the top of the menu once you upload it (or after you set one of the pre-existing options). When you are ready to apply the change to your profile, click the “Save” button.

Once saved, your new profile picture will immediately become visible to friends, followers, and other users on your Steam profile (unless you decide to make your Steam profile private).
Information source: howtogeek.com
