The five best Steam Deck apps for 2026 are Decky Loader, ProtonUp-Qt, Heroic Games Launcher, EmuDeck, and Flatseal—but they are essential for different reasons. SteamOS already includes the Steam client and Valve’s Proton compatibility layer, so you should not install all five automatically. Use Decky for Gaming Mode customization, ProtonUp-Qt for a specific compatibility-tool problem, Heroic for Epic/GOG/Amazon libraries, EmuDeck for legally owned retro games, and Flatseal when a Flatpak cannot access a file, drive, or device.
Which Steam Deck apps are actually essential?
There is no universal must-install list. SteamOS already includes the Steam client and Valve’s Proton compatibility layer, so most owners should add software only when it solves a specific problem. In 2026, the five most useful additions are Decky Loader for Gaming Mode customization, ProtonUp-Qt for managing extra compatibility tools, Heroic Games Launcher for Epic, GOG, and Amazon libraries, EmuDeck for emulation setup, and Flatseal for repairing Flatpak permissions.
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Install the apps that match your use case rather than all five. A minimalist Steam-only player may need none of them. Someone with an Epic library may need Heroic but never EmuDeck; someone troubleshooting an SD-card access problem may need Flatseal for five minutes and then never open it again.
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A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11| Your need | Best app | What it adds |
|---|---|---|
| Customize Gaming Mode | Decky Loader | A plugin layer for interface and quality-of-life controls |
| A Windows game needs a different compatibility build | ProtonUp-Qt | Graphical installation and management of tools such as GE-Proton |
| Play Epic, GOG, or Amazon games | Heroic Games Launcher | Library management and Linux game installation outside Steam |
| Set up legally owned retro games | EmuDeck | Emulators, configurations, controller mappings, and Steam integration |
| A Flatpak cannot see a file, drive, or device | Flatseal | Graphical control over Flatpak sandbox permissions |
1. Decky Loader: the best Game Mode customization layer
Best for: owners who want more controls and customization without repeatedly returning to Desktop Mode.
#1 Best Overall
- Compatible with Nintendo-Switch 1 (NOT Nintendo-Switch 2), smartphones, and tablets
- Boost your gaming experience with up to 160MB/s read for fast load times
- A2-rated app performance lets you quickly access and enjoy games and apps without lag for an enhanced gaming experience and a competitive edge
- Store more of your favorite games and other content with capacities up to 2TB
- Built to endure with temperature resistance, waterproofing, x-ray protection, and more
Decky Loader is a community-made plugin launcher for Steam Deck. It adds a plugin interface to Gaming Mode, where compatible plugins can provide menu styling, custom system sounds, screen-saturation controls, extra system settings, and other quality-of-life features. Its main advantage is convenience: once installed, many adjustments are available from the Gaming Mode interface instead of requiring a keyboard, terminal, or trip to the desktop.
Decky is not one standardized feature package. Each plugin is maintained separately, so stability, design quality, and compatibility can vary considerably. Treat the plugin browser as a collection of optional community tools, not as a guarantee that every listed plugin is equally safe or current.
How to install Decky Loader
- Open the Steam menu, choose Power, and select Switch to Desktop.
- Use a web browser to download the installer from the official Decky Loader project. Avoid unofficial mirrors and untrusted plugin sources.
- Run the installer and choose the stable release for normal use.
- Return to Gaming Mode. Decky should add its control to the Steam Deck’s Gaming Mode interface, where you can open the Plugin Browser and install individual plugins.
The project also documents a Konsole-based installation command, but the graphical installer is the better choice for most readers. Back up important data before making substantial system customizations, and do not install plugins from sources you cannot verify.
Decky Loader’s main drawback
Decky Loader is not a Valve application, and SteamOS updates can occasionally cause it to disappear or require reinstallation. If that happens, check whether the Decky release you installed supports your SteamOS branch, then reinstall it or move to the release branch recommended by the project. Use the stable Decky channel unless you specifically need a prerelease feature.
Decky can make the Deck feel more personal and expose useful controls, but it is not a frame-rate booster. Installing it will not automatically improve every game’s performance.
2. ProtonUp-Qt: the simplest way to manage extra compatibility tools
Best for: a Windows game or non-Steam launcher that does not behave well with the Proton versions supplied by Steam.
Rank #2
- Compatible with Nintendo-Switch 1 (NOT compatible with Nintendo-Switch 2), smartphones, and tablets
- Boost your gaming experience with up to 160MB/s read for fast load times
- A2-rated app performance lets you quickly access and enjoy games and apps without lag for an enhanced gaming experience and a competitive edge
- Store more of your favorite games and other content with capacities up to 2TB
- Built to endure with temperature resistance, waterproofing, x-ray protection, and more
ProtonUp-Qt is a graphical manager for installing and updating third-party compatibility tools, including community Proton builds such as GE-Proton. It can also manage Wine and Proton tools for applications such as Steam, Lutris, and Heroic Games Launcher. The interface is designed with handhelds and gamepads in mind, making it considerably less intimidating than manually creating compatibility-tool folders.
Start with Valve’s built-in Proton versions. Valve’s general guidance is that most users should use the Proton version supplied by the Steam client. ProtonUp-Qt becomes useful when a particular title has a known issue with the default selection, when a launcher requires a specific Wine or Proton build, or when you need to keep more than one community tool available.
How to install and use ProtonUp-Qt
- Switch to Desktop Mode.
- Open Discover, search for ProtonUp-Qt, and install the Flathub version. The project also documents an AppImage option, but Discover is the simplest route on Steam Deck.
- Open ProtonUp-Qt and select the platform or launcher you want to manage, normally Steam for a Steam game.
- Choose Add version or the equivalent install control, select the compatibility tool and release you need, and let the application place it in the appropriate directory.
- Return to Gaming Mode, open the affected game’s Properties, select Compatibility, enable the option to force a specific Steam Play compatibility tool, and choose the newly installed version.
Keep the number of installed versions manageable. If a game works with Valve’s default Proton, there is usually no reason to replace it simply because a community build exists. If you experiment, change one variable at a time so you can identify whether the compatibility tool actually helped.
What ProtonUp-Qt cannot do
ProtonUp-Qt installs and maintains compatibility tools; it does not run games, rewrite a title’s code, or guarantee that a particular GE-Proton release will fix a problem. A failure may come from the game, its launcher, DRM, the selected compatibility build, SteamOS, or a configuration outside ProtonUp-Qt. If a title stops working after a change, return to the previous Proton version or Valve’s default selection before troubleshooting further.
3. Heroic Games Launcher: one home for Epic, GOG, and Amazon libraries
Best for: Steam Deck owners whose PC libraries extend beyond Steam.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteHeroic is an open-source launcher for Linux, Windows, and macOS. On Steam Deck, it supports accounts and libraries from the Epic Games Store, GOG, and Amazon Games. Depending on the store and title, Heroic can install, update, repair, move, and launch games; configure Wine or Proton; download custom compatibility versions; display ProtonDB and Steam Deck compatibility information; and add installed games to Steam.
Rank #3
- Note: NOT compatible with Switch2 Please note that this product is not a microSD Express card and is not compatible with Switch2 for game storage or save data. If used in the Switch2, it may only support limited functions such as storing screenshots or videos, but will not allow game installation or save file access.
- Designed for dependable storage on portable gaming consoles
- Steam Deck users: For optimal gaming performance, including the ability to store and load video games, we suggest using a Gen4x4 2230 SSD.
- 5-year limited manufacturer warranty
- SmartPhones: S20, S20+, S20 ultra 5G, S10 lite, S10, S10+ A22, A22 5G, A52 5G, A32 5G, A52, A72, A32, A02s, A12, A21, A71 5G, A51 5G, A20s, Note 10+, J4 Core, J8, J7 Star, J7, Note 10 Plus. SAMSUNG TABLETS: Tab S7 FE 5G, Tab S7 FE, Tab A7 Lite, Tab A7 10.4 (2020), Tab Active 3, Tab S7, Tab S7+, Tab S6 Lite, Tab S6, Tab A 8.0 (2017), Book S and 10th Generation Fire Tablets.
That makes Heroic more than a shortcut generator. It gives non-Steam libraries a dedicated management interface while still allowing the games to appear in Gaming Mode after installation. It does not replace Steam for every game, however. Store features, launchers, DRM, cloud saves, controller behavior, and online services can differ from the Steam version, so check the individual game’s requirements rather than assuming every title will behave identically.
How to install Heroic on Steam Deck
- Switch to Desktop Mode and open Discover.
- Search for Heroic Games Launcher and install its Flatpak.
- Launch Heroic, sign in to the store accounts you use, and configure the game’s install location and Wine or Proton settings as needed.
- Install and update games from Desktop Mode.
- After installation, use Heroic’s Add to Steam control or its automatic Steam integration so the game appears as a non-Steam title in Gaming Mode.
Heroic’s Steam Deck guidance recommends managing the launcher and its installations in Desktop Mode. Running Heroic itself in Gaming Mode is not supported and can cause problems; use Gaming Mode primarily as the place where you launch games that Heroic has already installed and added to Steam.
External drives and SD cards
A Flatpak may not automatically have access to every folder on an SD card or external drive. If Heroic cannot see a library location, first confirm that the drive is mounted and that the chosen path is correct. Then inspect the app’s Flatpak permissions with Flatseal rather than granting every application unrestricted access. A narrow path override is preferable to exposing an entire home directory or the whole filesystem.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Heroic’s release cadence changes, so avoid judging the app by an old version number. Check the project’s current release information before publication or troubleshooting a newly reported issue.
4. EmuDeck: the most complete emulation setup helper
Best for: players who want to organize and play retro games they legally own without configuring every emulator by hand.
EmuDeck is designed for SteamOS and other supported handheld platforms. It automates much of the work involved in installing and configuring multiple emulators, setting paths, creating hotkeys and controller mappings, applying bezels and performance fixes, and integrating games with Steam. It can also set up front ends such as EmulationStation or Pegasus.
Rank #4
- EXPAND YOUR STORAGE. Insert your card to add massive storage up to 1.5TB[1] to your Android smartphones and tablets, digital cameras, and laptops.
- SPACE FOR MORE. With expansive capacities up to 1.5TB[1], capture and store hours of Full HD video[4], movies, music, games, photos, and podcasts.
- MOVE FILES FAST. Use your card with the SANDISK QuickFlow microSD UHS-I Card USB-A Reader[6] to achieve up to 195MB/s[2] read speeds [128GB-1.5TB models] and offload your content fast.
- LOAD APPS IN A SNAP. Rated A1[3], the SANDISK Ultra microSD card is optimized for faster app launch and overall app performance.
- EASY CONTENT MANAGEMENT. Easily back up, organize, and transfer your photos and videos with the SANDISK Memory Zone desktop or Android mobile app[5].
The surrounding toolset is part of EmuDeck’s appeal. Depending on the platform and current release, it may include utilities such as EmuDeck Compressor, BIOS Checker, cloud-save features, SteamDeckGyroDSU, and EmuDecky. You do not need to use every utility, but they help turn a collection of separate emulators into a more consistent handheld setup.
Recommended Free Tools
How to set up EmuDeck
- Switch to Desktop Mode and download the installer from the official EmuDeck project.
- Follow the SteamOS setup guide and choose the storage location and configuration style offered by the installer.
- Allow EmuDeck to install and configure the emulators. Depending on the setup, emulators may be installed as Flatpaks or AppImages.
- Place your legally obtained game files and required firmware in the locations specified by the setup.
- Use Steam ROM Manager if you want individual games to appear as non-Steam shortcuts, or use EmulationStation or Pegasus as a centralized library.
EmuDeck reduces repetitive setup; it does not remove the need to understand what files you own and where they came from. Its FAQ describes the software as a script that installs a suite of tools, and BIOS files are not included.
Important: EmuDeck does not supply ROMs or BIOS files
EmuDeck does not make copyrighted games, ROMs, or BIOS files legal to download. Use only games, ROMs, and firmware that you are legally entitled to use in your jurisdiction. The legality of creating or using a backup can vary by country, especially for firmware and games obtained from another source.
Storage planning for EmuDeck
Emulation libraries can grow quickly, and Heroic installations can consume the same limited internal storage. Steam Deck supports microSD storage, and Valve documents support for UHS-I Class 3 or better cards. Format the card through the Steam Deck’s storage settings before using it for a library; the exact menu wording can vary slightly by SteamOS release, but it is found under Steam > Settings > System and the storage or format controls.
If you need additional capacity, an UHS-I microSD card for Steam Deck is the most directly relevant accessory for EmuDeck and Heroic libraries. Choose capacity and a reputable card based on your storage needs, and do not assume that a higher advertised speed automatically produces a measurable improvement in every game. Always format the card through Steam Deck settings before moving a library to it.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →5. Flatseal: the permission repair tool for Flatpak apps
Best for: fixing an app installed from Discover that cannot see a file, folder, SD card, external drive, controller device, or other resource.
Best Value
- CAPTURE LARGER THAN LIFE. Unlock startling 5K[3] point-of-view and pristine high-res stills with video speed class ratings of U3 and V30[4].
- SPEED BARRIERS SHATTERED. Save precious moments with rapid read speeds up to 245MB/s[2] and write speeds up to 170MB/s[2] [256GB-1TB capacities[1]].
- MAXIMIZE WITH MASSIVE CAPACITY. Record longer and store more with up to 2TB[1] of storage.
- DURABILITY YOU CAN COUNT ON. SANDISK microSD cards are temperature proof, humidity proof, waterproof, shock proof, drop proof, magnet proof, X-ray proof and wear-out proof[7].
- EASY CONTENT MANAGEMENT. Easily back up, organize, and transfer your photos and videos with the SANDISK Memory Zone desktop or Android mobile app[10].
Flatseal is a graphical utility for inspecting and changing Flatpak permissions. Flatpak sandboxing is useful because it limits what an application can access, but the default permissions may not match your workflow. A launcher might be unable to read a library on removable storage, or a utility may not be able to access a device it needs.
Flatseal is therefore a troubleshooting tool, not a performance tweak, launcher, or compatibility layer. It does not make an unsupported game run faster and should not be installed merely because it appears in Discover.
How to use Flatseal safely
- Switch to Desktop Mode, open Discover, search for Flatseal, and install it.
- Open Flatseal and select the affected application from the list.
- Review the Filesystem, Devices, and related permission sections.
- Enable only the path or device access required for the task. If the app needs an SD-card folder, grant that folder or the narrowest relevant path instead of unrestricted access to the entire system.
- Close and restart the affected application. Flatpak permission changes may not take effect in an already running process.
More permissions mean less sandbox isolation. Do not broadly enable home-directory, root-filesystem, or device access just to make an error disappear. If you no longer need an override, remove it or restore the application’s default permissions.
Recommended combinations by Steam Deck owner
Most Steam-only players
Keep the stock Steam client and Valve’s supplied Proton versions. Add Decky Loader only if Gaming Mode customization appeals to you. Install Flatseal only when a specific Flatpak permission problem occurs.
Players with a difficult Windows game
Test the Proton versions already available in Steam first. Install ProtonUp-Qt if you have a documented reason to try GE-Proton or another community tool, then change only the affected game’s compatibility setting.
Epic, GOG, or Amazon players
Install Heroic from Discover in Desktop Mode, manage the library there, and add installed games to Steam for Gaming Mode access. Add Flatseal only if the Heroic Flatpak cannot access the chosen library path.
Retro-gaming players
Install EmuDeck, prepare legally obtained game and firmware files, and decide whether Steam ROM Manager or a front end such as EmulationStation better suits your library. Plan SD-card capacity before importing a large collection.
Free tools Windows power users keep installed
One-click scans. No signup required.
Optional Desktop Mode hardware
All five apps can be installed on the Deck itself, but Desktop Mode is more comfortable with a monitor, keyboard, mouse, Ethernet connection, or external storage. A Steam Deck dock or USB-C hub is optional rather than required; before buying one, verify its port layout, charging support, display output, and compatibility with your Deck model and peripherals. The apps do not require a particular dock.
What these apps do not guarantee
- None of them guarantees higher frame rates in every game.
- ProtonUp-Qt does not guarantee that GE-Proton will fix a title.
- Decky plugins are not a single standardized product and can break after SteamOS changes.
- Heroic does not replace Steam for every game or store feature.
- EmuDeck does not provide ROMs or BIOS files.
- Flatseal should not be used to grant broad permissions without considering the security trade-off.
- These are community or third-party tools, not applications officially endorsed by Valve.
The Bottom Line
Bottom line: Decky Loader is the broadest quality-of-life upgrade, but none of these apps is mandatory. Choose ProtonUp-Qt for a specific compatibility problem, Heroic for non-Steam PC libraries, EmuDeck for legally owned retro games, and Flatseal only when a Flatpak’s sandbox blocks something you need.
Quick Recap
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