Annotate PDF

About this Tool

Annotate PDF online free — highlight, draw, and add notes in your browser

You're reviewing a contract. You want to highlight a clause, add a note, and draw attention to a specific section. Without the right tool, you're printing, scribbling, and scanning back. TruePDFs Annotate PDF tool lets you do all of it directly in the browser. Free, no installation, no signup.

What this tool does

3 core tools — Draw, Highlight, and Add Text. Draw freehand on any part of the page. Highlight important sections. Drop a text note wherever you need one. Apply your changes and download the annotated PDF. Original content stays untouched. Annotations sit on top.

How to annotate a PDF

Step 1: Upload your PDF

Click "Select PDF to Annotate" and choose your file. Works on desktop and mobile.

Step 2: Pick your tool

Choose Draw for freehand markups, Highlight for marking text, or Add Text to drop notes anywhere.

Step 3: Mark up your document

Use your mouse or finger directly on the PDF preview. Mark what needs attention.

Step 4: Apply and download

Click "Apply & Download." Your annotated PDF is ready. Done. No signup. No watermarks. Free.

Who uses this?

Students and researchers

Highlighting key sections in research papers, adding margin notes to study material, or marking up textbook PDFs for revision.

Teachers and reviewers

Giving feedback on student assignments or drafts without printing a single page.

Legal and business professionals

Marking up contracts for review, flagging clauses that need discussion, or noting changes before sending back to the other party.

Designers and creative teams

Adding visual feedback directly on PDF mockups or presentation decks during review rounds.

Does it work on mobile?

Yes. Use your finger to draw, highlight, or place text notes on the PDF preview. No app needed — just open TruePDFs in your phone browser.

Are annotations permanent?

Yes. Once you click "Apply & Download," annotations are baked into the PDF. Keep a copy of the original if you need an unannotated version later.

Frequently asked questions

Is it free?

Yes. Completely free, no hidden charges.

What annotation tools are available?

Draw (freehand), Highlight, and Add Text. Cover most common review and markup needs.

Can I annotate on mobile?

Yes. Touch input works for drawing and highlighting on smartphones and tablets.

Do I need an account?

No. Upload, annotate, download.

Is my file secure?

Yes. Encrypted connection, files not stored permanently after processing.