AES-256 · Offline · No account

Your most important papers.
Nobody else’s.

UnderKey keeps your ID, passport, car papers and crypto seed phrases in an encrypted vault that never leaves your phone. Draw a pattern — that’s the only key.

Coming soon
Available on iOS and Android
  • Free for 10 items
  • No sign-up, no email
  • Nothing leaves your phone
9:41●●●

Draw your pattern

Try it — connect any 4+ dots

Add to vault

From Photos & Files

Locked.

0 files encrypted with AES-256.
They exist only on this phone.

  • No cloud, no account
  • Only your pattern opens it
  • Encrypted with your pattern
  1. 1Draw
  2. 2Select
  3. 3Lock
No cloud✦No accounts✦No tracking✦No backdoors
What goes inside

Everything worth
protecting.

The documents you’d panic about losing — and would hate to see leaked. Kept together, encrypted, and one pattern away.

01

Passports

Data page, visas, residence permits.

02

ID cards

Front, back and the numbers you always forget.

03

Car papers

Registration, inspection, insurance, driving licence.

04

Seed phrases

12 or 24 words, kept offline and out of cloud backups.

05

Certificates

Birth, marriage, diplomas, medical cards.

06

Secure notes

PINs, codes and anything you can’t lose.

Security without complexity

Serious encryption that feels
like unlocking your phone.

On-device AES-256

Files and metadata are encrypted on your phone. No servers, no shared keys — not even we can read them.

AES-256 · key derived from your pattern · stored nowhere

One pattern, one vault

Every pattern opens a different vault. Need a decoy? Just draw another pattern.

Expiry reminders

Never miss a passport, ID or insurance renewal. Reminders are local and never reveal what expires.

Seed phrases & notes

Store crypto recovery phrases offline, away from cloud backups and your photo roll.

Scan or photograph

Document scanner with auto edge detection, or import from Photos and Files. OCR suggests expiry dates on-device.

Auto-lock & protection

Locks the moment you leave the app and blocks screen capture on Android.

Plausible deniability

One pattern.
Different worlds.

There is no list of vaults to give you away. Every pattern opens its own encrypted space, so a second, harmless vault is just another shape you draw.

Expiry reminders

Never get caught
with an expired passport.

Add an expiry date once. UnderKey reminds you well ahead — locally, without the notification revealing what’s about to expire.

For crypto holders

Your seed phrase,
off the internet.

Type your 12 or 24 words once. UnderKey encrypts them on your phone and keeps them away from cloud backups and your photo roll.

Still keep a paper or metal backup. Why both matter →

How it works

Three steps. No setup.

  1. i.

    Draw your pattern

    Your pattern derives the key that encrypts the vault. It isn’t stored anywhere.

  2. ii.

    Add your documents

    Use the document scanner or import from Photos and Files. Everything is encrypted as it enters.

  3. iii.

    Leave the app

    It locks instantly. Your documents stay encrypted on your phone — nowhere else.

Pricing

Start free. Stay private.

Free for up to 10 items. All encryption, decoy vaults, and reminders included. Pro removes the limit.

Weekly
$1.99/week

Try Pro with no commitment.

Yearly
$19.99/year

Less than $2 a month.

Best valueLifetime
$39.99once

Pay once. Yours forever.

Guides

Store it properly.

All guides →

Where to Store a Crypto Seed Phrase Safely (2026 Guide)

Paper, metal, password managers or an offline encrypted vault? The trade-offs of every way to store your 12/24-word recovery phrase.

Read guide →

Should You Keep a Digital Copy of Your Passport? How to Do It Safely

Why a digital passport copy saves your trip when the original is lost — and how to store it without leaking it to the cloud.

Read guide →

How to Hide Photos on iPhone (Really Hide Them)

The built-in Hidden album, Locked Notes, and encrypted vault apps compared — what actually keeps private photos private.

Read guide →

Lost Your Passport Abroad? What to Do, Step by Step

Lost or stolen passport while travelling: police report, embassy, emergency travel document, cancelling the old one, and how to make it easier next time.

Read guide →

How to Keep Scans of Your ID and Passport Safe on Your Phone

Why storing ID scans in your camera roll or cloud is risky, and how encrypted offline vaults protect your most sensitive documents from leaks and hacks.

Read guide →

How to Track Document Expiry Dates (and Never Miss One)

Passports, IDs, licences and insurance all expire. A simple system with reminders prevents last-minute scrambles and missed renewals.

Read guide →

Offline vs Cloud Storage for Sensitive Documents: Which Is Safer?

Cloud storage is convenient but risky for passports, IDs and financial records. Offline encrypted vaults keep sensitive documents under your control.

Read guide →

How to Organize Family and Household Documents (Digital and Paper)

Birth certificates, insurance, wills, property deeds — a clear system for storing, backing up and sharing household documents when you need them.

Read guide →

How to Prepare a Travel Documents Kit (Digital and Physical)

What documents to pack, how to store digital copies securely, and how to prepare so losing your passport abroad is stressful but not catastrophic.

Read guide →
FAQ

Good questions.

Do I need an account?

No. There is no sign-up, no email and no login. You open the app, draw a pattern and your vault exists — only on your phone.

Can UnderKey see my documents?

No. Everything is encrypted with AES-256 on your device and never sent to a server. We don’t run one that could receive your files.

How do decoy vaults work?

Each pattern opens its own vault. Draw a second pattern, put a few harmless documents in it, and that’s the vault you open if someone insists.

What if I lose my phone?

UnderKey keeps nothing in the cloud, so there is no online copy for anyone to find — including you. Keep printed copies of truly critical documents somewhere safe.

Is it really free?

Yes, for up to 10 items total. All encryption, decoy vaults, and reminders are included. Pro removes the limit.