Mark up a PDF with highlights and notes
Highlight passages, underline, strike out, sketch and leave short notes while you read, then save a marked-up copy. The file stays in your browser and the marks become part of the page.
- Files never leave your browser.
- No account needed
- No watermark added
- Works on any device
How it works
Step 1: Choose a PDF and wait for the pages to appear.
Step 2: Select a mark such as Highlight, Underline, Strike-through, Draw or Note, and pick a colour.
Step 3: Drag over the text or area you want to mark, or click to place a note.
Step 4: Save and download the marked-up PDF.
How annotating works here
You read the PDF as page previews and mark it with a highlighter, an underline, a strike-through, a freehand pen, shapes, and text notes in the style of sticky notes. Each mark is placed by hand: you drag a rectangle over the words you want to highlight, because there is no automatic snapping to the selected text.
When you save, every mark is drawn onto the page content of the new copy. That is different from the comment objects that desktop PDF readers create, which stay separate from the page and can be edited later by anyone with the same reader. Here the marks are part of the picture of the page, so they look the same in every viewer, including phone previews and email thumbnails.
That choice is convenient for sharing, and it also means the marks can no longer be changed as annotations once the file is saved. Keep your original PDF, and reopen it if you want to start again.
Why use this tool
Looks the same everywhere
Because marks are drawn into the page, highlights and notes show up in every viewer, without depending on the reader supporting comments.
A full set of markup tools
Highlight, underline, strike out, draw shapes or freehand and add text notes from one toolbar, in the colours you choose.
Nothing leaves your device
The PDF is read and marked in your browser and not uploaded, which suits confidential drafts and study material.
Common uses
Studying a textbook chapter
A student highlights definitions in yellow and underlines formulas, then saves a copy to revise from on a tablet.
Reviewing a colleague's report
A reviewer strikes through sentences that should go and leaves short notes in the margin, then emails the marked-up copy back.
Checking a contract before signing
A freelancer highlights the payment and cancellation clauses and adds a question mark note beside terms to raise with the client.
Sketching over a diagram
An engineer circles a component on an exported drawing and adds an arrow and a one-line note for the team.
Supported formats
- Input
- PDF files (.pdf).
- Output
- One PDF file with the marks drawn on the pages.
To take marks back out of a file that uses real annotation objects, use Remove PDF Annotations.
Good to know
- Marks are drawn onto the page content of the saved copy, not stored as editable annotation objects, so they cannot be edited or deleted later in a PDF reader.
- Highlights are placed by hand as translucent rectangles. There is no automatic text selection, so you need to size each highlight to fit the words.
- Because the marks are part of the page, Remove PDF Annotations will not clear them; keep your unmarked original if you might want a clean copy.
- Password-protected PDFs must be unlocked first with Unlock PDF.
Your files never leave your browser
This tool runs entirely on your device using your browser. Your files are not uploaded to our servers and are not stored anywhere. Closing the tab discards everything.
Frequently asked questions
Are my annotations saved as comments in the PDF?
No. They are drawn onto the pages of the saved copy, so they look identical everywhere but cannot be edited afterwards as separate comment objects.
Does Annotate PDF upload my file?
No. The PDF is opened and marked in your browser and the saved copy is created on your device, so nothing is sent to a server.
Why does the highlight not follow my text exactly?
Highlights are translucent rectangles that you position yourself; there is no snapping to selected words. Zoom in and adjust the rectangle to fit the line.
Can I remove my annotations later?
Not from the saved copy, because they are part of the page. Keep your original file, and if you want to start over, annotate the original again.
What is the difference between Annotate PDF and Edit PDF?
Annotate PDF is built for reading and reviewing, with highlighting, underlining and notes. Edit PDF is for adding content to a page, such as text, images, stamps and cover boxes.