Chusko FAQ
Everything about Chusko, the peer-to-peer casting tool where your media never touches a server.
Ready to present a document? Follow the screenshot guides forcasting PDFs orcasting PowerPoint slides.
What is Chusko?
Chusko casts media between your devices. One device, the Projector, holds local files — videos, PDFs, and PowerPoint decks — and streams them peer-to-peer to another device, the Screen, which displays them. Playback is controlled from the projector: play, pause, seek, volume, and ±10 second skips for video; page navigation for documents.
Do my files get uploaded to Chusko's servers?
No. Media never touches a Chusko server. The only data that passes through our relay is a few kilobytes of WebRTC handshake (the connection setup). The bytes travel directly from the projector device to the screen device, peer-to-peer.
Is the stream encrypted?
Yes. The video travels over WebRTC, which encrypts the media with DTLS-SRTP end to end, from one device to the other. Even in the rare case that traffic falls back to a TURN relay because a direct connection isn't possible, the relay only forwards encrypted bytes it cannot read.
Where are the media bytes stored during playback?
On the devices themselves. The projector reads the file from its local storage; the screen caches the received bytes in the browser's IndexedDB on that device and serves them to its own video element. Nothing is stored on any server.
Do I need an account or signup?
No. Chusko has no accounts, no profiles, and no login. You open the page, pick a role, and pair with a room code.
How do I pair two devices?
One device picks the Screen role and hosts a room, which creates a 6-character room code (and a QR code). The other device picks the Projector role and enters the code, or scans the QR. The QR deep link even pre-fills the code for you.
Which video formats does Chusko support?
Anything the screen device plays natively: MP4, MOV, WebM, MKV, Ogg, and more. There is no remuxing and no container parsing. Files don't need to be fragmented or 'faststart'; even MP4s with the moov atom at the end play fine, and movies of any size work because the screen stores bytes on disk-backed storage.
Does Chusko work with PDFs and PowerPoint files?
Yes. PDF, PPT, and PPTX files open on the projector, which renders each page or slide into an image and sends only those images to the screen — the file itself never leaves your device. PDFs support single-, two-, and four-page layouts with rotation. Slides project as static images, so animations and transitions are not reproduced. The web app opens PDFs, PPT, and PPTX directly in your browser. The desktop app renders PowerPoint through a local LibreOffice copy.
Do I need PowerPoint or LibreOffice to present in the browser?
No. The web app renders PPT and PPTX locally in the browser without either installed. It accepts presentations up to 100 MiB, with an additional limit on unpacked data. Slides are static: animations, transitions, and embedded video do not play. Preview the formatting before presenting; exporting to PDF is an alternative when you need a fixed layout.
How do I control PDF pages in Chusko?
On the Projector, use Previous and Next or enter a page number and choose Go. PDFs have single-, two-, and four-page layouts and 90-degree rotation. PowerPoint has slide navigation but not the PDF layout controls. Password-protected PDFs need to be saved as an unlocked copy first.
Can more than one screen watch at the same time?
Yes. A room has one projector and can have as many screens as you like. A second projector joining the room is rejected.
Do both devices need to be on the same Wi-Fi network?
No. Chusko works over the internet. The devices connect through standard WebRTC NAT traversal (STUN), with a TURN fallback for networks that block direct connections. The TURN path still carries only end-to-end encrypted bytes.
What devices work with Chusko?
Devices running Chusko include Android phones and tablets, Android TV and Google TV, iPhone, iPad, Apple TV, and desktop computers. The web app also runs in modern browsers on phones, tablets, and computers. A typical setup is a phone as the projector and an Android TV or laptop browser as the screen.
What happens if the connection drops mid-session?
Sessions are designed to resume. The screen keeps the bytes it already received, so a reload or reconnect continues from where playback was, without re-sending the whole file. The projector also remembers its playhead across a reload.
Does Chusko show ads or track me?
No. There are no ads and no tracking. Because there is no account and media never touches a server, there is nothing to profile.
More detail on how the pieces fit together in How Chusko casts video peer-to-peer.