Built to get out of your way.

Why SyncBy!App exists

Every presenter knows the feeling: you arrive at a venue, and the next ten minutes are spent fighting a VGA adapter, borrowing someone's HDMI cable, logging into a shared laptop, or emailing your slides ahead of time and hoping nothing changes. Technology that was meant to help you connect instead disconnects you from your audience before you've said a word.

SyncBy!App was built to fix exactly that. Open it on any screen, pick up your phone, scan a QR code — and your slides are live. No account. No upload. No installation. Under 30 seconds from nothing to presenting.

How it works, technically

The presenting screen (projector, TV, browser) creates a session and displays a unique PIN. When you join with your phone, a WebRTC DataChannel is established between the two devices — a direct, encrypted peer-to-peer tunnel. Your PDF or images are rendered to WebP locally in your browser and sent directly to the screen, never touching a server.

If the network blocks WebRTC (as corporate firewalls sometimes do), the connection automatically and silently falls back to a WebSocket relay — the session continues without interruption. The server in that case acts purely as a message pipe; it receives encrypted chunks of image data and forwards them without storing anything.

Privacy by design

Your presentation content — slides, text, images — never reaches our servers. Period. Session metadata (anonymous PIN/UUID pairs) is held in memory and automatically deleted when the session ends. IP addresses used for rate limiting are one-way hashed (SHA-256) and never stored in a form that could identify you.

There are no tracking cookies, no third-party analytics, no advertising identifiers. See the Privacy Policy for full details.

Built to last

SyncBy!App provides everything you need to present for free — unlimited sessions, with each session lasting up to 3 hours.

For organizations that need custom branding, unlimited session durations, and full control over their data, we offer an Enterprise license — a self-hosted deployment running entirely on your own infrastructure, with no dependency on our servers.

What we're working on

The roadmap is focused on reliability, performance, and advanced presentation tools.