PDF Commenter

An Obsidian plugin for reading and annotating PDFs. Select text, leave comments, and link them to other notes in your vault with backlinks.

Comments are stored as individual markdown notes with frontmatter, not embedded in the PDF. Everything stays in your vault as plain files.

Desktop only.

Features

• PDF viewer with zoom controls and pinch-to-zoom
• Select text and create comments anchored to that position
• Comments pane sits alongside the PDF with scroll sync
• Each comment is a markdown note — edit it, link to it, find it in search
• backlinks autocomplete in the comment editor
• Highlighted text regions rendered on the PDF pages
• Right-click context menu: copy text, create comment, copy to active note

How it works

When you annotate a PDF, the plugin creates:

• A sidecar file (<pdf>.mg-comments.json) storing annotation positions and metadata
• A folder of markdown notes (one per comment) with frontmatter linking back to the PDF

Install

Via BRAT (recommended)

1. Install the BRAT plugin from Obsidian's community plugin browser (Settings > Community plugins > Browse, search "BRAT").
2. Open BRAT settings (Settings > BRAT).
3. Click Add Beta plugin.
4. Paste the repo URL: kirangathani/pdf-commenter
5. Click Add Plugin. BRAT will download the latest release and keep it updated.
6. Enable PDF Commenter in Settings > Community plugins.

Manual install

Download main.js, pdf.worker.js, styles.css, and manifest.json from the latest release and place them in your vault at .obsidian/plugins/pdf-commenter/.

Keyboard shortcuts

General

Shortcut	Action
Ctrl+Alt+M	Create comment from selected text
Alt+Backspace	Delete selected comment
Ctrl+Z / Cmd+Z	Undo last comment deletion
Alt+D	Cycle to next comment
Alt+Shift+D	Cycle to previous comment
Ctrl+F / Cmd+F	Open search bar
Escape	Close search bar / context menu
Ctrl+Scroll / Cmd+Scroll	Pinch-to-zoom

Comment editor

Shortcut	Action
Ctrl+Enter / Cmd+Enter	Save comment
[[	Open wikilink autocomplete
Arrow Up / Arrow Down	Navigate autocomplete suggestions
Enter	Accept selected suggestion
Escape	Dismiss autocomplete

Search bar

Shortcut	Action
Enter	Next search result
Shift+Enter	Previous search result
Escape	Close search bar

Build from source

npm install
npm run dev     # watch mode
npm run build   # production build

Requires Node 16+.