Privacy

Sinkro has no accounts, no analytics and no tracking.

What reaches the server

• The room code.
• Playback state: playing or paused, position, speed and a timestamp.
• The address and title of the page with the video, when someone creates a room or brings everyone to their video, so others can see what it is and go to it. They aren't sent just because you browse. They're encrypted with a key made from the room code and deleted with the room. The server also sees room codes, so this keeps them out of plain sight rather than hiding them from whoever runs the server.
• The length of the video you're watching, and the name of the site its player comes from, encrypted with a key made from the room code. Others are told when theirs is a different length, so everyone can pick the same player. They're kept with the room's playback state and deleted with it.
• A random number made when a page connects, so reconnecting after a network drop doesn't count you twice. It says nothing about you, and it isn't stored or used anywhere else.
• A name for you in the room, drawn at random from a list of adjectives and animals, such as "Calm Owl". You never type it, so it says nothing about who you are. It's encrypted with a key made from the room code, and the others see it next to what you do, like "Calm Owl paused the video". It's kept only while you're connected.
• How far your video is from the room's, in fractions of a second, so everyone can see how closely the room is in sync. It isn't stored.
• Whether you're on the room's video or not, so the others know who's with them. Never which page you're on instead. No one's name goes with it, and it isn't stored.
• Whether you're watching an ad, so others in the room can choose to wait. No one's name goes with it, and it isn't stored.
• When a room is created, a hash of your IP address, kept for at most a minute to limit how many rooms one address can create. Connecting to a room counts against a similar limit, held in memory only.

Video and any other page addresses or titles don't reach the server.

One exception, from how browsers work: the connection to a room is opened from the page with the video, so your browser tells the server which site that is, such as www.example.com, though not which page on it. Sinkro's server doesn't store or use it. Hosting providers can keep request logs; the hosted server is on Cloudflare.

What stays with you

• Your language, your random name, server address, and any video you picked by hand for a site are stored in your browser.
• An invite link carries the room code and the page address in the part of the URL browsers don't send to servers. Whoever you send it to can read both.
• While you're in a room, the address and title of the page you're on, to notice when you go to another video. They stay in your browser until you leave the room or close the browser.

How long it's kept

A room's playback state and video address and title are deleted 24 hours after its last person leaves, or after about 12 hours with people still in it but nothing played, paused or moved.

Why the extension asks to run on all sites

It has to find the video on whatever site you're watching. It connects to the server only for a tab you've put in a room.

Who runs the infrastructure

The default server and this page run on Cloudflare, which processes connections, including IP addresses, to deliver them. You can run your own server and set its address in the extension's settings.

Contact and your rights

Sinkro is run by its maintainer, gunesbro. For privacy questions or requests, open an issue on GitHub. Issues are public, so please don't include personal details. For anything that shouldn't be public, use GitHub's private reporting form.

Depending on where you live, laws such as the GDPR or KVKK may give you rights to access, correct or delete your personal data. Sinkro has no accounts, and what reaches the server isn't tied to your name, so there's usually nothing we can look up for you. Room data is deleted on the schedule above. To delete what's stored in your browser, remove the extension.

Check it yourself

Sinkro is open source: read the code on GitHub.