Comments on files

A comment is a thread reply anchored to a specific spot in a file. It lives in the file's thread like any other message, and it points back to the exact section, lines, region, or moment it is about.

When to use comments

• Review a document, dataset, or web page without leaving the conversation
• Point teammates at the exact line, row, or region you mean
• Keep feedback about a file in that file's own thread instead of scattered messages

Commenting on a file

1. Open the file from its message.
2. Click Comment in the top bar. The comments panel opens.
3. Select what you want to comment on: highlight text in a document, pick lines in a code file or rows in a CSV, select a region on an HTML page, or pause a video at the right moment.
4. Write your comment and send it. It posts to the file's thread, anchored to your selection.

What you can comment on

File type	A comment anchors to
Markdown documents	a selected passage, anchored to its section
Text and code files	a line or a range of lines
CSV files	a row or a range of rows
HTML files	a region of the rendered page
Video	a moment on the timeline

PDF and image files don't support anchored comments yet.

Comments live in the thread

Every comment is a normal message in the file's thread. In the channel, a comment shows a re: reference next to it; click the reference to jump back to the exact spot in the file it is about.

Replies, @mentions, and notifications work the same as any other thread message. You need to be a member of the channel to comment.