Steam Deck Storage Guide: microSD Cards, SSD Upgrades and Freeing Up Space

The easiest way to add storage to a Steam Deck is a reputable UHS-I microSD card, which the Deck formats itself and treats as extra library space. Move your most demanding games to internal storage through Settings > Storage, and keep slower-paced games on the card. Swapping the internal SSD gives you the fastest upgrade, but it means opening the device and reinstalling the system, so most owners should try a good card and some careful cleanup first.

A Steam Deck can feel roomy on day one and cramped two weeks later. Modern games are huge, and the Deck also stores data you may not realize is there, such as shader caches and compatibility files. The good news is that you have several ways to deal with this, and most of them cost little or nothing. This guide explains what kind of storage your Deck has, how to choose a card, how to organize games between internal storage and microSD, how to recover space, and how to troubleshoot a card that misbehaves. It closes with an honest look at whether opening your Deck for an SSD swap makes sense.

Key facts

• Valve lists the Steam Deck OLED with 512 GB or 1 TB NVMe SSD options, each with a high-speed microSD card slot.
• The microSD slot supports UHS-I and SD, SDXC and SDHC cards, according to Valve's specifications.
• Steam Deck microSD cards use ext4 with casefolding, and the Deck formats cards to the proper format itself.
• Valve says that games stored on a microSD card appear in your library as soon as the card is inserted.
• Steam Deck supports booting from microSD and multi-boot, per Valve's FAQ.
• Replacement parts and repair guides for Steam Deck are offered through iFixit in collaboration with Valve.
• Each Steam account on a Deck keeps its own local save data and settings.

Understanding what your Deck has

Steam Deck models differ, and that makes a difference to the choices that make sense for you.

Valve's current specification page lists the Steam Deck OLED with 512 GB and 1 TB NVMe SSD options. Original LCD models were sold with 64 GB, 256 GB and 512 GB configurations. To check yours, go to Settings > System, or look at Settings > Storage to see how much space you have in total.

Your real free space is always going to be less than the advertised figure. SteamOS itself needs room, and storage is measured differently by manufacturers and operating systems. A "512 GB" drive never shows 512 GB available for games.

All versions include a microSD slot, which makes this the obvious first step for almost everyone.

Choosing a microSD card

Valve's specifications say the slot supports UHS-I and SD, SDXC and SDHC cards. Not all cards labeled at that standard perform equally well, so here is what to look for.

Buy a known brand from a reputable seller. Counterfeit cards are a real problem online. A fake can report a large capacity and then silently fail once you pass its true size. Very cheap 1 TB or 2 TB cards from unknown sellers are the most likely offenders.

Look for A2 and U3 or V30 ratings. These markings indicate that the card has been tested for better random access and sustained writes, which matter for games. A2 refers to app performance. U3 and V30 refer to sustained write speed.

Pick a size that suits your library. A card should cost noticeably less per gigabyte than an SSD upgrade would, and you will benefit from buying a bit more than you think you need.

Be realistic about the maximum speed. UHS-I tops out far below what an internal NVMe drive can do. Thankfully, the difference between a good card and an SSD is often smaller in practice than the raw numbers suggest, particularly with many indie and older games. Large open-world games are where you are most likely to notice longer loads and occasional stutters.

Setting up a new card

1. Insert the card into the slot on the bottom edge of the Deck, with the label side facing the correct way for your model. Do not force it.
2. Go to Settings > System and find the option to format the card.
3. Confirm. This will erase anything on the card.
4. When it has finished, the card appears as a storage location.

Valve says the Deck handles formatting itself, so you do not need to prepare the card on a PC first. A card formatted on the Deck uses ext4 with casefolding, which is what SteamOS expects. Windows cannot normally read this format without additional tools, so do not expect to plug the card into a PC and browse your games. If Windows offers to format the card when you insert it, say no unless you want to erase it.

Moving games between internal storage and microSD

You can move games at any time without redownloading them.

iFixit's troubleshooting guide describes the same process: open Settings > Storage, find the game in the internal or microSD list, and press the Y button to move it. Its guide also says that you may see improved stability by moving a problem game from microSD to internal storage.

Here is a sensible division of labor:

The Deck also lets you choose where a game is installed at the time you download it, so get into the habit of picking the right place from the start.

How to free up space on a Steam Deck

Before you buy anything, see whether you can reclaim enough space for free.

Check what is actually using it. Go to Settings > Storage and sort by size. It is common to find a game or two you finished months ago.

Uninstall what you are not playing. You do not lose your license, and cloud-enabled saves will come back when you reinstall the game. Before you uninstall a game that does not use Steam Cloud, back up the saves. Our guide to Steam Cloud saves explains how to check.

Be aware of shader caches and compatibility data. The Deck stores precompiled shaders and Proton files for each game. These folders live in steamapps/shadercache and steamapps/compatdata. They can take up a lot of room in total, but they also speed up loads and hold important data. In particular, compatdata may contain saves for games that are run through Proton. Do not delete those folders blindly. Community-made cleaning tools are available, but they deserve caution, as you should only use well-regarded tools and read what they delete first.

Remove leftover content from uninstalled games. Compatibility data sometimes stays behind after a game is removed. In Desktop Mode you can look for orphaned folders. If you are not comfortable working with this, leave it alone. Lost space is better than lost saves.

Trim optional content. Some games offer language packs or high-resolution assets as optional DLC. Uncheck these in the game's properties where possible.

Be selective about mods. Large mods can quietly use many gigabytes. Check their sizes in your game's folder and remove the ones you are no longer using.

Using multiple cards

Because Valve says that games on a card appear right away, you can treat microSD cards almost like game cartridges. Keep one for your RPGs and another for your indie games, and swap them as needed.

Follow a few simple rules:

• Do not remove a card while a game is running or while the Deck is writing to it. Fully close the game first.
• Label your cards. A tiny piece of tape on the case makes things simple.
• Keep them in a proper case. These things are extremely small and very easy to lose.
• Remember that a card formatted for one Deck uses ext4, and it is not ideal for sharing with a Windows PC.

Be aware that games on a card cannot be played if the account that owns them is not signed in, or if the game requires a connection and you are offline. Valve says that once a game is on disk, you can play it while offline, unless that game itself requires an internet connection.

Fixing a microSD card that is not recognized

If your card disappears or the Deck refuses to read it, go through these checks.

Restart the Deck. Hold the power button and select Restart. A surprising number of temporary issues clear this way.

Remove and reinsert the card. With the Deck off, take out the card, check that the contacts are clean and put it back.

Update SteamOS. Go to Settings > System and check for updates. Software fixes for storage issues are not unusual.

Check the slot and the card. Try the card in another device, or try another card in your Deck. This single test tells you whether the card or the Deck is at fault. iFixit keeps a troubleshooting page for cards that are not recognized, and it notes that the Deck functions best with ext4.

Reformat as a last resort. If the card appears but does not work properly, format it on the Deck. This erases what is on it, but your Steam games can be downloaded again.

Heat can be a factor. A card in a hot device under heavy loads can be less reliable. Good cards handle this better, which is another reason not to buy the cheapest one that you can find.

If a disk write error shows up, our guide to the Steam disk write error covers more detailed troubleshooting.

Should you upgrade the internal SSD?

Replacing the internal drive is possible, and Valve has worked with iFixit so that parts and repair guides are available. Valve's FAQ responded to the question of how easy it is for users to replace the SSD with a video, because in its words the answer is "a bit complicated". It is fair to treat this as a serious repair and not as a casual upgrade.

Before you open your Deck, think about the following.

You have to reinstall the system. A new drive does not come with SteamOS. You will need to create recovery media from Valve's recovery image and install it, then download your games again.

The drive has to physically fit. The Deck uses a small form factor drive. Check iFixit's guides and the part's specifications for your exact model before buying, because not every M.2 drive will fit. iFixit's community answers also address the differences between models, which matters if you have a base eMMC version.

There is a risk of damage. Screws strip, clips break and cables can tear. If you are not experienced, consider having a repair shop do it.

Warranty implications vary. Coverage depends on your region and on what actually goes wrong. Read the terms that apply to you before opening anything.

You might not notice much difference. Upgrading capacity is the main benefit here. If your only problem is running out of room, a large microSD card solves it at much lower risk.

Think of an SSD upgrade as most worthwhile when you have a low-capacity base model, you are comfortable with small electronics, and you want your biggest games on fast storage.

Installing non-Steam games and managing their storage

Valve's FAQ confirms that you can run non-Steam games through Proton and add them just as you would on the desktop client. Launchers for other stores and emulators can take up a lot of space, though, and might not appear in the Storage menu in the same way.

When you are working with these:

• Use Desktop Mode's file manager to see what is using your space.
• Keep non-Steam game installs in a dedicated folder, so that you can find them later.
• Back up emulator saves separately, since Steam Cloud will not protect them.
• Be careful with what you download. Only install software from sources that you trust, and be especially careful with so-called free download sites. Our article on free game download risks lists the warning signs.

Multiple accounts on one Deck

Valve says that Steam Deck supports multiple accounts, with each account keeping its own local save data and settings. That is handy for a family, but keep in mind that installed games take up space for everyone. If your household is sharing a Deck, agree on who gets to keep what installed, and look at our Steam Families guide for the sharing rules.

Streaming as an alternative to more storage

If you have a capable gaming PC at home, you may not need to install your biggest games on the Deck at all. Steam Remote Play lets you stream a game from your PC to your Deck, which takes up no storage on the Deck. It needs a good home network to be enjoyable. It is particularly useful for huge, rarely played games. Our Remote Play Together guide covers the settings that affect streaming quality.

Valve also says that you can use a Steam Deck as a PC controller via Remote Play, which is a nice bonus if you want to play on your PC from the sofa.

Storage habits that prevent problems

• Keep at least 10 percent of internal storage free. Updates need working room, and a full drive leads to failed patches.
• Update games while the Deck is charging, and let large updates finish before you go out.
• Review your library each month and remove what you have finished.
• Check how much room a game needs before buying. The figure on the store page may not include future updates.
• Put new games on the card first, and move them to internal storage only if they perform poorly.

Is it worth buying a higher-capacity model instead?

If you are about to buy a Deck, compare the price difference between models against the price of a good microSD card. Larger models may have other benefits, so weigh up the whole package and not simply the storage. For owners considering how to pay, our guide to buying a Steam Deck with Steam Wallet funds explains what works, along with our Steam Deck refund policy explainer in case it turns out not to be for you.

A cheaper route to more games is to wait for sale events and build up a little credit over time. XPReward offers one modest way of doing that: create an account, complete offers from the Offers page to earn points, and redeem them for Steam gift cards once you have enough. The smallest card is currently $25 for 3,600 points, so it will not pay for a microSD card overnight, and offers depend on your country.

Frequently asked questions

What microSD card should I buy for a Steam Deck?

Buy a UHS-I microSD card from a known brand and a reputable seller, ideally rated A2 and U3 or V30. Valve's specifications say the slot supports SD, SDXC and SDHC cards. Avoid suspiciously cheap high-capacity cards, as fakes are common.

Do I need to format a microSD card before using it on a Steam Deck?

Yes, but the Deck does it for you. Valve says it formats cards to the proper format, which is ext4 with casefolding. Use the format option in Settings > System. This erases what is on the card, so back up anything you need first.

How do I move games to my SD card on a Steam Deck?

Open Settings > Storage, select the drive holding the game, highlight the game and press Y to move it. You do not need to redownload it. If a game runs poorly on the card, you can move it back the same way.

Why is my Steam Deck storage full when I have few games?

Shader caches, compatibility data, screenshots, mods and system files all use space. Check Settings > Storage to find what is largest. Be careful when deleting compatibility data, because it can contain saves for some games that run through Proton.

Can you upgrade the Steam Deck's internal SSD?

Yes, and iFixit sells parts and publishes guides in collaboration with Valve. It is a real repair, however. You will have to reinstall SteamOS, make sure that the drive fits your model, and accept a risk of damage. A microSD card is much simpler.

Are games slower on a microSD card?

Often somewhat, especially large open-world games with heavy streaming, although many games run fine. If a game stutters or loads slowly, try moving it to internal storage. iFixit's guide also notes that moving a game can improve stability.

Can I use one microSD card across two Steam Decks?

Games on the card can appear when it is inserted, but the account that owns them must be signed in. Do not rely on this for sharing purchased games. Steam Families is the official way to share games between household members.

Can a Windows PC read a Steam Deck microSD card?

Not without extra tools, because Valve says Deck cards use ext4 with casefolding, which Windows does not read natively. Windows may offer to format the card when you insert it. Decline, or you will erase everything on it.

Sources

• Steam Deck FAQ, for microSD format, boot support, accounts, offline play and repair parts.
• Steam Deck Tech Specs, for storage options and supported card types.
• iFixit: Steam Deck Not Recognizing SD Card, for moving games and card troubleshooting.
• iFixit: Steam Deck OLED Storage parts, for replacement storage.

Card recommendations reflect common buying practice. Specifications checked on 8 November 2026 and can change with new models.