Skip to content


NotebooksLearn about notebooks vs. projects

Observable is a great place to publish notebooks that engage readers, teach new concepts, and challenge assumptions: they start conversations. In Observable, you can discuss your work right in the notebook by adding Comments to specific cells.


If you are subject to or witness abuse by another user please contact You can refer to our Code of Conduct for more clarification. If you see an offending comment you can report it directly by using the menu on the comment and choosing "Report spam or abuse."

Adding comments

To add a comment, click on the comment icon () to the left of any notebook cell or open the Cell menu (), then choose Add comment. A text window will appear immediately below the cell. Add your comment, then click Comment.

Screen shot showing text window that appears where a user would add a new comment immediately below the selected cell.
Add and confirm comments.

Joining a thread

When viewing a notebook, others' comments are hidden by default to limit distraction from the notebook content. If there are already comments on a notebook cell, a number appears next to the comment icon in the left margin indicating the number of comments in the thread. For example, the cell below has an existing thread with three comments:

Screen shot showing the number 3 next to the comment icon in a notebook, indicating three comments on that cell.
Thread size is indicated next to the comment icon.

To add to the thread, click on the comment icon in the left margin to reveal all existing comments. To add your own, click the + Comment button at the end of the thread.

Screen shot showing an existing notebook comment, with a button that says '+ Comment' at the bottom of the thread where a user can add their own comment.
Thread size is indicated next to the comment icon.

Who can comment?

Generally speaking, comment visibility matches notebook visibility. For example, as a notebook transitions from private to link-shared to published, so will the comments on that notebook.

This means that if you've shared a notebook with a colleague or friend and used comments for feedback, when you publish your notebook those comments will become visible to everyone. If you don't want this to happen, you can delete these comments before publishing.

Who can see comments?

Anyone who can see the notebook can also see its comments. For public notebooks, this means anyone can see the comments. Members of team workspaces can have private conversations in private team notebooks. Comments on link-shared and published notebooks are visible to any viewers of the notebook, however. When you comment, your comments will appear on the notebook, and the notebook's authors will be notified.


On notebooks you edit or comment on, you'll receive email notifications for each new comment someone else makes. If you'd rather not receive email notifications for a given notebook, you can unsubscribe using the link in the email or through the notebook menu () in the top right and choosing "Disable notifications."

If you change your mind and wish to resubscribe to a specific notebook or want to be alerted of comments without leaving a comment yourself, use the same menu () and choose the "Enable notifications" option.


To get somebody's attention or to loop them into a comment, you can mention a user using the @ symbol and their username. If the mentioned user has access to the notebook, they will receive an email with the content of the comment, as well as a link to the notebook it appears in.

Locking, editing or deleting comments

Locking comments

As an author, you can disallow others from commenting on your notebook by locking comments from the notebook menu () via Settings.

Screen shot showing modal window through a notebook's Settings where a user can choose to Lock comments.
Lock comments through notebook Settings.

Editing and deleting comments

Notebook owners can delete any comments. To delete a comment, open the comment thread by clicking to the left of any cell. Then, click the three dot icon () to the right of any comment to reveal options to Edit or Delete. Immediately below each comment, you will also see a Resolve option, which you can use to tidy up threads or track progress while addressing comments.

Screen shot showing menu with options to Edit or Delete a notebook comment.
Resolve, edit or delete notebook comments.