Best Vault Apps to Hide Photos and Files on Android
You want a few photos and documents tucked away behind a PIN or your fingerprint, so a friend scrolling your gallery or a lost phone does not expose them. That is a reasonable thing to want, and Android can do it. But there is a catch worth saying up front: a lot of "vault" apps lock a folder without actually encrypting anything, and a couple of famous ones used encryption so weak it was a joke to break. So before you trust any app with your private files, it helps to know the difference between a PIN that hides things and encryption that protects them. This guide starts with what is already on your phone, then covers the apps worth installing, and stays honest about what each one really does.
Start with what is already built in
The features baked into your phone are usually the safest choice, because they are maintained by the people who made the operating system and they tie into the phone's own secure storage. Try these before you install anything.
If you have a Samsung Galaxy, you already have Secure Folder. It creates a separate, encrypted space backed by Samsung Knox, with its own apps, gallery and files, all locked behind a PIN, pattern or fingerprint. To move a photo in, open Gallery, press and hold the photo, tap More, then Move to Secure Folder. You can also hide the Secure Folder icon entirely from Settings, Security and privacy, More security settings, Secure Folder, so nobody knows it is there.
On phones running Android 15 or newer (with more than 6GB of RAM), there is Private Space. It is a sealed-off profile at the bottom of your app drawer. When locked, the apps inside vanish from your app list, recent apps, notifications and settings, and you can hide the space itself so it does not show at all. From Android 16 QPR2 onward you can move files and photos into it too. Set it up from Settings, Security and privacy, Private space.
If you are not on Samsung and do not have Private Space, Files by Google has a Safe Folder. Open the app, hold a file, tap More, then Move to Safe folder, and set a PIN. One warning that catches people out: that PIN cannot be reset, so if you forget it the files are gone for good.
What a PIN lock actually does (and does not do)
This is the part most listicles skip. 
Many vault apps simply move your files into a hidden folder and put a PIN screen in front of the app. The files themselves sit on storage unchanged. Anyone who plugs the phone into a computer, pulls the storage, or uses a file recovery tool can often read them straight off the disk, because the lock was only ever on the app's front door, not on the files.
Real encryption scrambles the file contents with a key derived from your password, so the bytes on disk are useless without it. That is the protection you actually want for anything sensitive. A PIN that only hides an album is fine for keeping a nosy houseguest out of your gallery. It is not protection against someone technical who has your unlocked-storage device.
So match the tool to the threat. Hiding from a casual snoop? A built-in folder or a simple hider is enough. Worried about theft, repair shops or a determined person? You want genuine encryption, ideally from code that has been audited.
The fake-encryption history you should know about
The reason to be picky is not paranoia, it is precedent. The most cited example is NQ Vault. It advertised AES encryption, but a security researcher showed in 2015 that it used single-byte XOR, which is about the weakest scrambling there is, and only on the first 128 bytes of each file. The rest of the file was left completely untouched. So your "encrypted" photo was almost entirely readable, and the protected part could be undone in seconds. The company behind it had separate fraud accusations on top of that.
The lesson stuck: an app saying "military-grade encryption" on its store page proves nothing. Plenty of vault apps make claims their code does not back up. You cannot easily inspect a closed-source app, which is why the safest non-built-in option is software whose code is open and has been independently audited.
Cryptomator: open source and audited
If you want real encryption you can verify rather than trust, Cryptomator is the standout. It is open source, uses AES-256, and encrypts each file individually, plus the file and folder names, into a vault you can keep on your device or in cloud storage. Because the code is public it has been independently audited (Cure53 in 2017), so the encryption claim is one outside experts have checked rather than a marketing line.
It is less of a tap-and-hide gallery app and more of a proper file vault, so there is a small learning curve. You create a vault, set a password, then move files in. The Android app is on the Play Store, and a free F-Droid build exists too. For documents, backups and anything genuinely sensitive, this is the option that holds up. Pair it with one of the file manager apps for Android to move files in and out without fuss.
Mainstream vault apps and what they really offer
Among the dedicated photo-vault apps, Keepsafe (Private Photo Vault) is the long-running one, around since 2011. It gives you PIN and biometric locking, album organisation and cloud sync. Its paid tier adds a Fake PIN (a decoy vault), album locks and break-in alerts that photograph whoever enters a wrong PIN. Be clear-eyed about the model, though: its cloud storage uses keys the company holds, so it protects files in transit and on their servers, not as zero-knowledge encryption only you can open. And the Keepsafe icon is well known, so its presence signals you have a vault.
A handful of apps disguise themselves as a working calculator, opening the vault only when you type a secret code. That stealth is genuinely useful against a casual look, but check the same things you would for any app: does it actually encrypt, or just hide? Treat the disguise as convenience, not as security on its own.
Whatever you choose, read recent Play Store reviews and the listed developer before installing. Abandoned vault apps are common, and an unmaintained one can lose your files in an Android update.
Decoy vaults and how far they go
A decoy or fake vault gives you two PINs. One opens your real hidden content; the other opens a separate, harmless-looking vault you can show if someone pressures you to unlock it. Keepsafe's Fake PIN and several calculator-style apps offer this.
It is a clever idea with real limits. It helps in a casual or coerced situation where someone glances and moves on. It does not stop anyone who knows the trick exists and simply asks for the other PIN, and it does nothing about the underlying question of whether your files are encrypted at all. Think of a decoy as social cover, not a technical safeguard.
Lock the apps themselves, and keep the gallery tidy
Hiding files is one layer. Stopping someone from opening the apps that show them is another. If your phone or your chosen vault lacks a per-app lock, a dedicated locker can sit in front of your gallery, messages or file browser. See our roundup of app lock apps for Android for options that pair well with a vault.
On the everyday side, many gallery apps for Android now include their own hidden or locked album, which can be enough if you only need to keep a few shots out of the main grid. For a wider look at privacy and storage helpers, browse the tools and utilities hub.
Layering these is sensible: a built-in encrypted folder for the sensitive material, an app lock on the apps that touch it, and a tidy gallery so private shots never land in the main feed in the first place.
Frequently asked questions
Is a PIN-locked vault app the same as encryption?
No, and this is the key thing to understand. Many vault apps only hide files behind a PIN screen while the files stay readable on storage. Real encryption scrambles the file contents so they are useless without your key. For anything genuinely sensitive, choose a built-in encrypted folder or an audited open-source tool like Cryptomator rather than a simple hider.
Why is the NQ Vault story still worth mentioning?
Because it shows that an app's encryption claim can be completely false. NQ Vault advertised AES but actually used single-byte XOR on just the first 128 bytes of each file, which was trivial to undo. It is the reason to prefer software whose code can be inspected, or features built by the maker of your phone's operating system.
What is the safest option that is already on my phone?
It depends on your device. Samsung phones have Secure Folder, backed by Knox encryption. Phones on Android 15 or later with enough RAM have Private Space. Other phones can use the Safe Folder in Files by Google, though note that its PIN cannot be reset, so do not forget it.
What does a decoy or fake vault actually protect against?
It gives you a second PIN that opens harmless content, useful if someone casually pressures you to unlock the app. It does not help against anyone who knows the feature exists and asks for the real PIN, and it does not make your files encrypted. Treat it as social cover, not technical security.
Can hidden files survive a factory reset or be recovered?
If the app only hid the files without encrypting them, recovery tools can often pull them off storage even after deletion. Truly encrypted files are unreadable without the key, so a reset that wipes the key effectively destroys them. That difference is exactly why encryption matters more than hiding.
Should I use cloud sync for my vault?
Only if you know how the keys are handled. Some vaults sync to servers with keys the company controls, which protects against theft of your phone but means the provider could in principle access files. Zero-knowledge or client-side encryption, where only you hold the key, is the stronger choice for cloud backup.