How to annotate a PDF
- Choose your PDF. The first page opens with the Highlight tool ready.
- Drag across the words you want to mark, the way you select text. The mark snaps to whole words and follows the lines; drag down to take in several lines of a paragraph. Switch to Underline or Strikethrough the same way, and pick a colour from the swatches.
- To add a comment, tap Comment in the small bar next to the mark and type it. Use Note to put a sticky note anywhere, Draw to circle or sign, and Box to frame a table or picture.
- Move between pages with the page buttons, add your name if you want it shown as the author, and click Download annotated PDF.
Example: reviewing a contract
Say a three-page rental agreement needs two changes. On page 1, highlight "The rent is due on the 1st of each month" and add the comment "Can we make this the 5th?". On page 2, strike through "30 days" in the notice clause and put a note beside it saying "45 days, as agreed on the phone". The list under the page now shows three annotations: a highlight on page 1 with its comment, a strikethrough and a note on page 2. After you download, the other person opens the file in their own reader and sees each mark with your comment, name and the date, and can reply or mark it as done there. The contract's own text is exactly as it was.
What each tool saves
| Tool | Saved in the PDF as | Good for |
|---|---|---|
| Highlight | Highlight annotation over the words | Key points, terms to check |
| Underline | Underline annotation | Points to agree or quote |
| Strikethrough | StrikeOut annotation | Words to delete in an edit |
| Note | Text annotation (sticky note) | Questions and longer comments |
| Draw | Ink annotation | Circling, arrows, initials |
| Box | Square annotation | Framing a table, figure or signature spot |
Tips
- Tap or click a mark to open its comment box again; use Select to move notes, drawings and boxes, or the arrow keys to nudge them (Shift for bigger steps). Delete removes the selected mark, and Ctrl+Z undoes.
- On a phone, zoom in before marking small text: spread two fingers on the page or pick a Zoom level, and move around with two fingers. One finger marks, draws and places notes.
- Highlights snap to the words pdf.js finds on the page, so they line up with the text even on small fonts. Text that runs vertically or at an angle can't be selected by dragging; use a box there.
- Annotations already in the PDF stay as they are. The list under the page shows only the ones you add here, and each one can be opened from the list.
- Without a mouse, Tab to the page and press Enter to add a note, type it, and move it with the arrow keys.
Related tools
To change the page itself (add text, white-out, images), use the PDF Editor. To lock the marks into the page, use Flatten PDF. To read a PDF with search and thumbnails, use the PDF Viewer, and to sign one, Sign PDF.