Hidden Letter
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A PRIVATE LITTLE WORLD.

Hidden
Letter.

An ordinary picture.
An extraordinary thing inside.

Hide a message, a memory or a moment.
Let the right person find it.

Meet Hidden Letter For iPhone
In 12 languages
NOT EVERY STORY BELONGS IN YOUR FEED.

01 / CREATE A SECRET

Five letter types.
One ordinary picture.

Write, record or choose a file. Hidden Letter encrypts it inside a cover image, ready for someone to unlock.

Your words, kept close.

Write a note or a personal letter, then tuck it into a cover image. Your words appear when the letter is unlocked.

Capacity depends on the cover image and hiding mode.

Three ways to hide your letter.

Whisper

Speed and more space

Seal

Balanced and JPEG-friendly

Phantom

Stealth and strong protection

TEXT LETTER
Hidden Letter: creating a text letter
A private letter, hidden inside a picture.

02 / CONTROL HOW IT OPENS

More than a password.
Make the moment matter.

Set the conditions when creating your letter. The recipient needs to meet them to reveal the hidden content.

01

Password lock

Protect the letter with a password. Add an optional clue to help the right person remember it.

For someone who knows the secret.
02

Time lock

Choose a future date and time. Keep the content locked until the moment you have selected.

For birthdays, anniversaries or later.
03

Location lock

Choose a place and an unlock radius. The recipient needs to reach that area before opening it.

For a destination worth going to.

Unlock QR code

Pair the original secret image with its unlock QR code. The letter's password, time and location conditions still apply.

Quick Unlock

When enabled, use device authentication on your own device. Time and location requirements still apply.

03 / KEEP & DISCOVER

Organize your secrets.
Discover nearby stories.

Two different ways to explore Hidden Letter: your own collection, and secrets connected to real places.

YOUR COLLECTION

Secret Library

A dedicated home for letters you create and import.

  • Find the right letter

    Search by title or content type.

  • Filter your collection

    Browse by format or by created and imported letters.

  • Share or remove

    Long-press a letter to access sharing and deletion.

Your collection
Hidden Letter: Secret Library with saved letters
SECRET LIBRARY
BEYOND YOUR COLLECTION

Secret Map

Leave an encrypted secret where you are. Explore what is nearby.

  • Publish at your location

    Create a secret point with a password and an unlock range.

  • Discover nearby

    Find the five nearest secrets and unlock them with the right password.

  • Manage your footprints

    Review and remove your published secret points.

Hidden Letter: Secret Map nearby secrets
NEARBY SECRETS

Secret Map uses an internet connection and location access.

04 / FROM YOU TO THEM

Create. Protect. Share.

From your first idea to the moment it is revealed, the process stays simple.

  1. 1

    Choose what goes inside

    Pick a cover image and add one of the five supported content types.

  2. 2

    Set your protection

    Select a hiding mode and add the unlock conditions that suit your letter.

  3. 3

    Send the original

    Share the secret image and its unlock QR code. The recipient opens them in Hidden Letter.

Keep the original intact. Screenshots, editing and compression can damage the hidden content. Share the original file and keep a backup of anything important.

HIDDEN LETTER FOR IPHONE

Make your first secret.

Five content types. Personal unlock rules. A whole new way to share.

Get Hidden Letter Available in 12 languages