Offline · app

Appearance

Light theme

Dark terminal vibes by default

Notifications

Sound on new message

Subtle chime when receiving

Desktop notifications

Requires permission

Haptic feedback

Mobile only

Privacy

Show typing indicator

Let contacts see when you type

Read receipts

Show when you've read messages

Link previews

Off = even more private

Auto-delete account

Wipe after inactivity

Account auto-deletes if unused

Identity

Your ID

$OFF wallet · Injective

Connect an Injective wallet

Optional. Links a wallet on this device only — never sent to the server, never tied to your Offline ID. Used for $OFF features.

Offline Pro

Free plan

Privacy isn't pay-to-win — encryption, .onion, dead-man-switch, multi-device are free for everyone. Pro is a way to support the project and get a visible supporter badge.

Price— $OFF

Pays to—

Security & verification

App integrity hash (SHA-256)

Compare with the hash on github.com/offlineapp/offline. If they match, you're running the published code.

computing…

Encryption

All messages and calls use end-to-end encryption. The server cannot read content, only routing metadata (sender/recipient ID).

ECDH P-256 (key exchange)
AES-GCM 256-bit (message encryption)
SHA-256 (fingerprints & integrity)
HMAC-SHA1 (TURN credentials)
Web Crypto API only — no custom primitives

What the server CAN see

• Your ID and recipient's ID (for routing)
• Packet size and timestamp
• Your IP (kept in RAM only, not logged)
• Online/offline status while connected

What the server CANNOT see

• Message content (encrypted before send)
• Call audio/video (P2P via WebRTC)
• Your contact list (stored locally)
• Your name, profile, or any identity info
• Group keys (generated locally, exchanged E2E)

Anti-traffic-analysis (active)

• Constant-size packets (1KB/4KB/16KB/64KB buckets)
• Continuous dummy traffic (~30s jittered)
• Rotating session tokens (10 min)
• Randomized send delays (30-200ms)
• Tor hidden service available

Cryptographic protocols

• Double Ratchet (Signal Protocol) — forward + post-compromise
• Sealed sender (server doesn't see who sent)
• End-to-end ECDH P-256 + AES-GCM 256
• Ephemeral keys destroyed after each message

Sign in on another device

Use this identity on another device

Generate a one-time sign-in code that lets you log in on another browser, computer, or phone with the SAME identity (same ID, same contacts will work). Anyone with this code can impersonate you. Don't share it. Don't screenshot it. Use it once and discard.

Welcome to Offline

Restore your identity

Your ID

Scan QR

Settings

Verify identity

New group

Encrypted notes

Select a contact