You need to review a 30-page proposal and send feedback to the author. Printing and handwriting comments is slow. Adobe Acrobat Pro DC has annotation tools but costs $19.99/month. PDFKits Annotate PDF adds notes, highlights, underlines, strikethroughs, and freehand drawings to any PDF in your browser. Free, no signup, no upload. The result is a standard PDF that opens with annotations visible in Adobe Reader, Preview, and every other viewer.
This tool covers the typical reviewer's workflow: highlight key passages, add sticky notes with explanations, draw arrows to specific content, strike through deletions. Each annotation is positioned on the page and can be moved, resized, or deleted before export. The original PDF content is preserved exactly — annotations are added as a separate layer compatible with the PDF specification's annotation standards.
Upload the file. PDFKits renders the pages with a navigation sidebar.
Pick an annotation type from the toolbar: Highlight (yellow, pink, green, blue), Note (sticky note with text), Underline, Strikethrough, Draw (freehand), Arrow, or Rectangle. Click and drag on the page to place the annotation. Click an existing annotation to edit its text or move it.
Click Export PDF. PDFKits saves the annotations as standard PDF annotation objects compatible with all viewers. The annotated PDF downloads to your device. Recipients see your highlights and notes inline when they open it.
Editors, lawyers, and managers review documents from team members, highlighting critical sections, leaving sticky notes with clarifications, and striking through outdated content. Faster than printing and scanning.
Researchers annotate journal articles with their interpretations, link findings to related work via notes, and highlight quotable passages for later citation. The annotated PDFs become personal research archives.
Students mark up textbook chapters with their own examples, key definitions, and exam-relevant passages — turning standard PDF textbooks into personalized study guides.
Designers, copywriters, and product managers share mockups and drafts as annotated PDFs, with arrows pointing to specific issues and notes explaining the change request.
Most browser-based annotation tools either lock features behind subscriptions (Smallpdf), require signup (iLovePDF), or upload your file. PDFKits annotates in your browser using pdf-lib — your file stays on your device. Annotations export as standard PDF annotation objects, so recipients see them in any viewer. Free, no signup, supports all common annotation types.
Yes. PDFKits exports standard PDF annotations that render in Adobe Reader, Preview, Chrome PDF viewer, mobile PDF apps, and every other viewer that respects the PDF specification.
Yes. Click any annotation to select it, then drag to move or use corner handles to resize.
Yes — they're standard PDF annotation objects. Recipients can add their own annotations, edit yours, or delete them in any annotation-capable PDF reader.
Use our Optimize PDF or Edit PDF tools after annotating — they flatten annotations into the page content, making them permanent.
Annotations are a separate layer that doesn't modify the original content. Editing (via Edit PDF) modifies the page content itself.
Yes, you can annotate any PDF. For text-based annotations (highlight, underline), the PDF needs a text layer — run OCR PDF first if it's a pure scan.