Steam is the online storefront for PC gaming, and the place that started off digital-only gaming. With the release of the Steam Deck, Valve has all but ensured Steam's place for many years to come. But it's not the only place to buy PC games, or even the only place to buy games that are redeemed through Steam. You can get game codes from a number of approved partners, or you can buy games from publishers that have their own launcher for downloading and playing games, in much the same way that Steam functions. Here's how to get those games attached to your Steam account, so you can play them all in the same place.

Why you might want to shop outside of Steam

It's all about choice (and discounts)

Steam might be the biggest PC game storefront, but it's far from the only one. Bundle sites like Humble Bundle offer large collections of older games for drastically reduced prices, and you can get new titles from them as well. Then there are big retailers like Amazon or Gamestop, authorized key resellers like Greenmangaming, and gray-market sites. We recommend sticking to the official partners, as gray market keys have been known to be revoked.

The main reason you would want to purchase from one of these other sites, and not just from Steam directly, is that you get the same game but you can find great discounts. Steam does have huge sales throughout the year, but it won't have everything you want on your wishlist at reduced prices, and by shopping around you can get a discount.

Adding game keys purchased from third-party sellers

Wherever you purchased your code to unlock a game on Steam, it's a quick process to associate that game with your Steam account, so you can use it. It's the same process whether your game code came in a retail box from a physical store, or from an approved online reseller like Amazon, Humble Bundle or Greenmangaming. Once linked to your account, you can install it on any computer that you are signed onto Steam on, but you can usually only play it on one PC at a time.​​​​​​

1. Open up Steam, click on the Add a Game button at the bottom-left, then select Activate a Product on Steam.
2. Enter the Product Code that the third-party storefront supplied when you purchased the game, and click on Confirm.

Assuming the key you received from the seller is legit, Steam will associate that game with your account, so you will be able to install it anywhere you are signed in to Steam.

You can also redeem codes on the Steam Deck, but the option is slightly hidden from view.

1. Tap the Steam button in the lower left corner, then select Settings.
2. Scroll down and select Library.
3. Select Add game from the right pane, and enter the code for your new game.

Once associated with your account, the new game will show up in the recently played games section on the Home menu. That makes it easy to download it to play later.

If you have the Steam mobile app installed, and you should, so you can secure your account with Steam Guard two-factor authentication, you can also add game keys from your phone. The option is slightly hidden, so here's how to access it.

1. Open the Steam Mobile app.
2. Tap on Wallet, then Redeem a Steam Gift Card or Wallet Code.
3. Enter your game key, and confirm.

Like any of the other methods, this will associate the game with your Steam account. Maybe the next time Valve overhauls the mobile app, they can make it more apparent that this is the correct thing to tap on.

And finally, you can also redeem game codes from the Steam website.

1. Go to store.steampowered.com/account/registerkey and sign into your account.
2. Enter the game code in the box, select the checkbox to agree to the terms, and click on Continue.
3. Confirm adding the game to your account.

Adding games from external storefronts to Steam

Steam also has the ability to be the launcher for any other game, regardless of where it was purchased. If they're installed on your PC, you can add a link to your Steam Library, so you can launch it without having to leave Steam. It's worth mentioning that you won't get achievements, trading cards, or any of the other social features of Steam while playing games in this way.

1. Open Steam and click on Add a Game in the bottom-left corner, then click on Add a Non-Steam Game.
2. Mark the checkboxes next to the already-installed games or launchers from other storefronts that you want to add to Steam, then click on Add Selected Programs.
3. Check your Steam Library pane and the game(s) you added from other storefronts should be shown.

It's worth remembering that this is essentially a shortcut to where you already have the games installed, so that you can launch them from inside Steam without having to open another launcher. You won't be able to uninstall them from Steam, so you'll have to manage them from the other storefront's launcher.

Adding third-party storefronts to the Steam Deck

The Steam Deck is arguably the best way to play your Steam library wherever you are. With its custom-built Linux operating system built around the new Steam Dashboard, you might be wondering if you could add and play games from other storefronts on your console. Well, you can, if you put in a little bit of work.

The Epic Games Store can be added, either through the Heroic Games Launcher (recommended) or through emulating the Epic Games Launcher with Proton. It's not just one storefront either, as Heroic also works as a launcher for GOG and Amazon, giving you an easy way to play all of those Prime Gaming titles you've possibly picked up over the years. You can also add EmuDeck, to emulate a wide range of games from older consoles, or the Java version of Minecraft.

While you can install and play games from non-Steam storefronts, they have a higher chance of running into issues or bugs. It's recommended to install a custom version of Proton on your Steam Deck, and keep it updated to the latest number, so you have the highest chance of game-breaking bugs being fixed.