How to reply and start a thread

Two different tools that people reach for interchangeably and should not. A reply answers one message. A thread takes a whole tangent out of the channel.

When do you want each?

Use a reply when your message answers a specific earlier one and the conversation is short. The reply stays in the channel, so everybody sees it in flow.

Use a thread when a topic is going to take twenty messages and would otherwise bury the channel. Thread messages stay out of the main timeline entirely.

The rule of thumb: if two people are about to have a ten-minute exchange that the other eight people in the channel do not need, that is a thread.

How do you reply?

Hover a message, or tap it on a touchscreen, and click the blue reply arrow in the little toolbar that appears.

A Replying to… line shows above the composer with an × to cancel. Send, and your reply carries a small preview of the original above it.

Click that preview to scroll back to the original. It scrolls when the original is inside the loaded history; if it is far back, load older messages first.

The person you replied to is notified, provided they can still see the channel and have not muted it.

How do you start a thread?

Two ways, and they mean different things.

From a message: hover it and click the violet speech bubble, name the thread, and you land in it. The message it came from is pinned at the top under "Thread started from".

About something new: the + New thread button above the composer, with a name and an optional first message.

Name threads properly. The name is what everybody else sees in the sidebar and in the channel's Threads strip, and "Re: that thing" helps nobody.

Where do threads appear?

Three places. A Threads strip at the top of the channel with a reply count on each. Nested under their channel in the sidebar. And as a "3 replies →" link on the message that started one.

A thread has its own page with a back link to the channel, and the same composer, tagging and attachments as a channel.

The Threads strip holds the newest active threads, so a channel that has been running for a year still shows a readable list.

How do you finish with a thread?

Archive it from the channel's Threads strip: hover the row and click the archive icon. It leaves the strip and the sidebar.

Archiving asks for no confirmation and is not something you undo from the interface, so archive a thread when the conversation is genuinely finished rather than as a way of tidying up temporarily.

Archiving hides a thread. It does not delete anything that was said in it.

Two things that surprise people

Thread messages never appear in the channel timeline. That is the whole point, and it means a link to a thread message points at the thread page rather than the channel.

Opening a thread does not mark the parent channel read. They are counted separately, so a channel can still show unread after you have read its busiest thread.

Does a thread have its own notification setting?

No, it follows the parent channel's. Set that from the bell in the channel header, per How to mute or follow a channel.