a simple video chat app... with benefits.

How does this work?

Usage is pretty simple. You create a room, share the link with your friends and wait for them to join.

Just keep in mind that room and session names are case-sensitive. This means room 'Test' is another room than 'test'.

Hint: Try to keep room names simple and avoid special characters, umlauts, etc. (as those will have to be encoded for the room to be reachable internationally, which makes the URL look 'weird'.)

Why can't I join a room?

If you want to join a room in which a video chat is going on, having a video camera and microphone is mandatory. Both must be properly connected and activated in your system settings. When joining a room you will be asked to grant access to both of them. If you don't grant access (or they can't be accessed due to others reasons) you won't be able to see or hear other participants.

I don't see any text messages?!

Text chat is currently work-in-progress. Messages are for your own privacy NOT stored on a server, meaning you can only see text messages as long as you stay in a room or until you reload the page.

Other participants can't hear me!

Don't panic, in most cases you only need to adjust your mic sensitivity in your system settings. If this doesn't help, make sure no other program is accessing your mic (some apps tend to 'reserve' the mic, so that no other app can access it at the same time). If another app is using your mic, close the app, restart your browser and try joining a room again. (Also make sure to select the correct audio input device when joining a room.)

Why do I have to scroll to see others?

You don't have to. If there are more participants in a room than can fit on your screen, just try zooming out a bit. On most PCs you just need to press CTRL - (both keys at the same time). If you want to return to the default zoom level press CTRL 0. On mobile devices try 'Request Desktop Site'.

Screen Sharing

Screen sharing works best in Firefox.

If you are using a webkit-based browser like Chrome / Chromium you can use a workaround by starting your browser from shell or command line with the following tagline: --enable-usermedia-screen-capturing. Full example command (assuming you are using Chromium in Linux):

chromium-browser --enable-usermedia-screen-capturing

In Windows you can create a link and edit its properties accordingly.


Encryption is enabled for all of this app's components, and its JavaScript APIs can only be used from secure origins (HTTPS or localhost), meaning that all data transferred using this app is encrypted.

In the case of RTCDataChannel, the encryption used is Datagram Transport Layer Security (DTLS), which is based on Transport Layer Security (TLS). Since TLS is used to secure every HTTPS connection, any data you send on a data channel is as secure as any other data sent or received by your browser.

More fundamentally, since Catchat is a peer-to-peer connection between two or more user agents, the data never passes through the web or application server. This reduces opportunities to have the data intercepted.