JavaScript
Channel Type

Channel Types

SendBird service provides two basic types of channels. Each type is designed and implemented for various use-cases of our customers’ businesses. The following summarizes the differences between the two and their characteristics.


Open channel

An open channel is a public chat by nature and it can handle a large number of participation online. In this channel type, anyone can easily participate in the chat without permission. A single open channel can accomodate up to 1,000, simultaneous users like Twitch-style public chat. This default number of participants can increase per request.

  • Ephemeral: In an ephemeral open channel, its messages are not saved in the database of the SendBird system. So the old messages lifted up by new ones can't be retrieved because they are one-time data. On the other hand, in a persistent open channel (by default), its messages are stored permanently in the database.

Group channel

A group channel is a chat that provides close interactions among limited number of people. By default, a user can join the chat as a new member through an invitation by another user who is already a member of the chat room. But by using various properties for its abilities, you can design and make various types of group channels which are fit to your use cases, such as Twitter-style 1-to-1 direct messaging, WhatsApp-sytle closed group chat, and so on.

  • Distinct: A distinct group channel is always reused for the same members. In case that a new member is invited, or a member leaves the channel, then the distinct property is disabled automatically. With the distinct property, you can reuse the group channel for the same members like Twitter Direct Messages-style 1-on-1 chatting.

  • Public: A public group channel can take any users with no invitation. Users can easily join the channel if they want to. On the other hand, a private group channel (default setting) accepts the invited users only.

  • Ephemeral: In an ephemeral group channel, its messages are not saved in the database of the SendBird system. As such, the old messages that scroll up beyond a user's display due to new messages can't be retrieved. On the other hand, in a persistent group channel (default setting), its messages are stored permanently in the database.


Open channel vs. Group channel

Open channelGroup channel

Open and visible to

Anyone within the application

Who is invited if private (Anyone if public)

Number of people

Up to 1,000 participants

Up to 100 members (can be increased per request)

How to create

Dashboard / Platform API / Client SDK

Platform API / Client SDK

Ephemeral messaging

Supported

Supported

Add users as friends

Supported

Supported

Operators

Supported

Supported

Ban user

Supported

Supported

Mute user

Supported

Supported

Freeze channel

Supported

Supported

Push notifications

N/A

Supported

Unread counts

N/A

Supported

Read receipts

N/A

Supported

Typing indicators

N/A

Supported

Mention others in message

Supported

Supported

Chatbot interface

N/A

Supported

Spam flood protection

Supported

Supported

Smart throttling

Supported

N/A