Annotate PDF Online Free
Highlight, underline, comment, draw, and stamp directly on your PDF — mark up contracts, mockups, and assignments the way you would on paper. Everything runs locally in your browser and downloads as a standard, compatible PDF.
Drop your PDF here
Verified facts
Check access, supported files, limits, and processing before choosing a document.
The core task does not require an account.
A PDF annotator lets you add notes, highlights, drawings, stamps, and text comments to a PDF. Saved annotations use standard PDF structures intended for compatible PDF viewers.
- Price
- Free — no account needed
- Account
- Not required
- Processing
- Processed locally in your browser without an application document-processing request
- Formats
- File limit
- No fixed limit — capped only by device memory
- Browser support
- Chrome, Firefox, Safari, Edge
What is a PDF annotator?
PDF Annotate is a browser-based tool that lets you highlight, comment, and mark up PDF documents. Choose PDF, use the controls above to configure the result, then download or use the resulting PDF. The core workflow runs locally in your browser without an application document-processing request. See formats, limits, and processing.
A PDF annotator lets you add notes, highlights, drawings, stamps, and text comments to a PDF. Annotations are saved using standard PDF structures intended to appear in compatible desktop, browser, and mobile viewers.
Annotation is the primary way professionals review, mark up, and collaborate on PDF documents. A legal team marks up a contract with comments on specific clauses. A teacher circles errors on a student's work. An editor highlights passages to cut or expand. EditPDF AI's annotator runs entirely in the browser — your document never leaves your device.
Practical examples
Common ways people use this tool in real documents and day-to-day workflows.
Highlight key passages, add margin notes, and bookmark important pages in textbooks, papers, and research articles.
Mark up reports, proposals, contracts, and design briefs with comments and corrections before returning them to the author.
Add written feedback, circle errors, and highlight strong sections on student assignments submitted as PDFs.
Annotate PDF mockups and proofs with specific change requests, sticky notes, and freehand drawings for revision rounds.
At a glance
Focused workflow
Highlight, comment, and mark up PDF documents.
Supported workflow
Accepts PDF and produces PDF. No fixed application limit; practical capacity depends on browser memory and device performance
Access and processing
Core tool with browser-based document processing.
How it works
- 1
Upload your PDF
Open the PDF you want to annotate. It loads directly in the browser-based editor.
- 2
Add annotations
Highlight text, add sticky notes, draw freehand, insert text boxes, or use shapes from the annotation toolbar.
- 3
Save and download
Click Save. The annotations are embedded in the PDF for compatible viewers, including Adobe Reader.
Formats, limits & privacy
Confirm that your file is supported and understand how this tool handles document data.
All annotation happens in your browser — your PDF never leaves your device.
PDF Annotate vs. doing it manually
Open this comparison if you are deciding between the browser workflow and a manual process.
Compare the workflows
Print a document, mark it up by hand, then scan it back in to share feedback.
Highlight, comment, and draw directly on the PDF — no printer or scanner needed.
Email back a separate list of comments disconnected from the document.
Comments stay attached to the exact page and location they refer to.
Worry the recipient's PDF viewer won't show your markup.
Annotations are saved as standard PDF objects visible in Acrobat, Preview, and other major viewers.
Frequently asked questions
Guides & real-world workflows
Ready to use PDF Annotate?
Highlight, comment, and mark up PDF documents Return to the tool above to choose your file, or browse the complete PDF toolkit for another task.