Compare
Silo vs PIN-only photo locker apps
| Silo | PIN-only photo locker apps | |
|---|---|---|
| What the PIN does | Your PIN or passphrase is run through Argon2id to produce the key that unlocks the vault. Without it the files stay encrypted. | Usually checks the code on the app screen. Whether the files depend on it varies.How to check: Ask the developer in writing whether the PIN is used to encrypt files or only to open the app. |
| Files encrypted at rest | Yes. XChaCha20-Poly1305 with 256-bit keys, written to storage only in encrypted form. | Varies. Many store ordinary files inside the app's folder. Some encrypt.How to check: Look for a named cipher and a published description. If there is none, assume the files are plain. |
| What opens it | A PIN of 6 or more digits, or a passphrase (Pro), plus optional face or fingerprint unlock. | Usually a 4 to 6 digit PIN, sometimes a pattern, often with face or fingerprint unlock.How to check: Count the digits it accepts. A 4-digit PIN has only 10,000 combinations. |
| Account needed | No. There is no sign-up, no email and no server account. | Varies. Some ask for an email, often to offer a reset.How to check: Go through setup in airplane mode. |
| Works offline | Yes. | Usually, for what is on the phone.How to check: Open a saved photo in airplane mode. |
| If you forget the PIN | Your 12, 6 or 2-word recovery phrase. Nobody can reset it for you, including Silo. | Varies. Some email a reset, some have a security question, some have no way back.How to check: Search the app's help page for forgot or reset, and note who can do it. |
| Verified import | Yes. Each item is read back and compared before Silo offers to remove the original. | Usually not described. Imports and removals often happen with no check.How to check: Import a test photo and look for a step that confirms the copy. |
| Export everything | Yes, on any plan, including after a plan ends. | Varies. Some allow one item at a time, some bulk, some only on a paid plan.How to check: Try exporting ten items in one go. |
| Published format and decrypt tool | Yes. The format is public, with a free independent decrypt tool. | Usually no. |
| Backup and who holds the keys | Arriving with launch: encrypted on the phone, then sent to your own cloud storage. Silo's developer cannot read it. | Varies. Some offer cloud backup through the company's servers.How to check: Find out where a backup goes and whether you or the company holds the key. |
| What happens on uninstall | The vault lives inside the app, so removing the app removes it. Export first, or keep a backup. | Often the same. Photos kept inside the app go with it.How to check: Uninstall a test copy with one photo inside and see whether it is still in your library. |
| Ads and tracking | No ads. Diagnostics are off unless you agree in setup. | Free versions often show ads. Some include analytics or advertising tools.How to check: Read the privacy label in the store listing. |
| Price | Free for up to 100 photos and 10 videos. Pro from $1.99 a week, $19.99 a year or $39.99 once. | Free with ads, with paid upgrades. Varies. |
A PIN is the simplest lock there is. You set four or six digits, and the app asks for them every time. Photo locker apps built this way have been popular for years because they are quick to understand.
Why people choose a PIN-only locker
- Simple. One code and nothing else to set up.
- Fast. Photos are a tap away.
- Often free. Most let you start without paying.
- Familiar. It works like the lock on your phone.
Where a PIN-only locker is enough
For keeping a few photos away from a casual look, a PIN locker is fine. It is a good fit when:
- the people nearby are curious, not determined;
- you won’t be storing anything that would cause real harm if copied;
- you only want a quick way to tuck photos out of the main grid.
A simple app with a clear exit and no account can do that well. If you pick one, run the checks in the table first.
Where it falls short
A PIN guards the door, not the files. The code is checked by the app. If the files inside are ordinary files, getting around the app can get around the lock. A PIN only protects the files when it is part of how they are encrypted, and in many apps it isn’t.
Short PINs are easy to guess. Four digits make 10,000 combinations. That is fine against a quick try and thin against anyone with time.
Recovery is often an email. Resetting by email is handy and it means someone other than you can reset your lock.
Few exits. Many lockers have no verified import, no bulk export, and no published format. If the app stops working or the company goes away, your photos can be stuck.
Uninstalling can lose everything. Photos kept only inside the app go when the app does.
How to decide
Ask what the PIN is for. If it is a screen to keep casual eyes out, a PIN locker does that. If it is meant to protect the files if the phone is lost, borrowed or copied, you need encryption where your code is part of the key.
Then ask about the way out: can you export everything, what happens on uninstall, and who can reset the lock?
If you want to move
Switching is safe if you go slowly. Export your photos from the old app first, at full quality. Import a small batch into the new one and open a few to confirm they look right. Only then delete from the old app, and keep your originals somewhere until you are sure. Don’t uninstall the old app until the last photo has been checked, because removing it may remove whatever is left inside.
What Silo does differently
Silo uses your PIN or passphrase to derive the key that encrypts every file, so the lock and the encryption are the same thing. It asks for at least 6 digits, gives you a recovery phrase instead of an email reset, verifies each import, lets you export everything, and publishes the format.
Questions
Is a PIN lock the same as encryption?
No. A PIN lock decides who gets past the app screen. Encryption scrambles the files themselves, so they are unreadable without the key. An app can have one without the other.
Is a 4-digit PIN enough?
For stopping a quick look, often yes. Against someone who can try codes quickly or copy the files, 10,000 combinations is small. Silo asks for 6 or more digits, or a passphrase.
What is the risk of an email reset?
It makes recovery easy, and it means whoever controls that email, or the company, can also reset your code. Real end-to-end encryption can't offer that.
Can I move photos out of a PIN locker into Silo?
Yes. Export them from the old app at full quality, import them into Silo, wait for the verified check, and only then delete them from the old app.