Highlights & Comments

Outerline lets you mark up a document without touching the Markdown. Highlights colour a passage, and comments attach a note to an exact stretch of text. Both are stored beside your library in Outerline’s metadata folder, so your .md files stay clean and portable.

Highlight Text

Select the text you want to mark, right-click it, and pick a colour from the swatches at the top of the menu. Five colours are available: yellow, green, blue, pink, and purple.

Right-click an existing highlight to Copy Link to Highlight, which puts an outerline:// deep link to that exact passage on the clipboard, or Remove Highlight to clear it.

Add a Comment

Select the text you want to comment on and press ⇧+⌘+C, or choose Format > Add Comment…. A popover opens at the selection. Type your comment and press ⌘+Return or choose Save Comment. The command is unavailable when nothing is selected.

Each document supports up to 500 comments.

Review Everything in the Markup Panel

Press ⌥+⌘+A or choose Editor > Show Markup to list every highlight and comment in the current document, each with the date and time it was created. Click an entry to jump to it in the text.

From a comment in the panel you can Edit Comment, Copy Link to Comment, or Delete Comment.

When the Text Changes

Highlights and comments are anchored to the text you selected. If you later edit or delete that passage, the anchor may no longer resolve, and the entry is shown as Text not found in the Markup panel. The comment body is preserved, so you can still read it and delete it when you no longer need it.

Where They Are Stored

Markup lives in Outerline’s data folder beside your notes, not in the Markdown itself. Because it travels with your library, highlights and comments follow you between Mac and iPhone when both apps point at the same library. Opening a note in another Markdown editor shows the plain text with no markup applied.

Markup and AI Tools

Outerline’s MCP server can read and create markup, so an agent can review what you highlighted or annotate a draft for you. See the MCP Guide for get_annotations, list_comments, create_annotation, and create_comment.

On iPhone

See Links & Tags on iPhone for the iPhone highlighter and the inspector’s Markup tab.