Mark up PDF documents with pen, highlighter, and drawing tools. Full Apple Pencil support with pressure sensitivity. Review, comment, and collaborate on documents directly from your iPhone.
Review a contract on your commute—highlight the clause that needs revision. Read a report in a coffee shop—circle the key findings. Grade student papers on your couch—mark corrections directly on submissions.
PDF annotation on iPhone means your markup tools are always in your pocket. No need to print, no need to wait until you're at your desk. Review and annotate whenever inspiration (or deadline) strikes.
Annotated PDFs share seamlessly. Send marked-up documents via email, drop them in shared folders, or upload to collaboration platforms. Recipients see your annotations in any PDF reader—no special software required.
Free-form drawing for handwritten notes, circles, arrows, underlines, and any mark you need. Natural ink-like strokes with smooth rendering. Write in margins, draw attention to specific areas, or sketch quick diagrams.
Semi-transparent highlighting for emphasizing text without obscuring it. Draw over important paragraphs, key terms, or sections requiring attention. The classic study tool, now digital.
Seven colors available: red (urgent/errors), orange (warnings), yellow (standard highlight), green (approved/correct), blue (information), purple (questions), and black (notes). Color-code your annotations for organized review.
Adjustable line thickness from fine (2px) for detailed notes to bold (15px) for eye-catching marks. Fine lines for margin notes, thick strokes for unmissable callouts.
ScanLens annotation is powered by Apple PencilKit, providing professional-grade drawing capabilities:
Press harder for thicker strokes, lighter for thin lines. Natural handwriting feel that responds to your pressure just like pen on paper. Write naturally, get beautiful results.
Angle your Apple Pencil to shade large areas quickly with highlighter. Upright for precision, tilted for coverage. The same techniques you use with real art supplies.
Rest your hand naturally on the screen while drawing. ScanLens ignores palm contact and only registers Apple Pencil input. Write comfortably without worrying about accidental marks.
Ink appears instantly as you draw—no lag between pencil movement and screen response. The immediate feedback makes annotation feel natural and responsive.
No Apple Pencil? No problem. All annotation tools work perfectly with finger input on any iPhone or iPad:
Large touch targets for tool selection and color picking. Easy to use even on smaller iPhone screens. No precision stylus required for basic markup.
Pinch to zoom into documents for detailed annotation areas. Draw fine details at high zoom, then zoom out to see the full page. Precision through magnification.
Swipe with highlighter tool to mark important text. Large finger strokes work well for highlighting—the semi-transparent color covers text cleanly.
| Step | Action | Tips |
|---|---|---|
| 1 | Open PDF in viewer | Scan new or import existing PDF |
| 2 | Tap markup button | Toolbar appears with tools |
| 3 | Select tool and color | Pen for notes, highlighter for emphasis |
| 4 | Draw on document | Zoom for detail work |
| 5 | Use undo if needed | Correct mistakes instantly |
| 6 | Save or export | Annotations embedded in PDF |
Mark changes needed, circle errors, add approval signatures. Track revision requests visually. Send annotated PDFs back with clear feedback for authors or designers.
Highlight clauses for discussion, mark requested changes, note questions in margins. Visual markup makes contract review collaborative and clear.
Students highlight key concepts, add study notes, mark formulas to memorize. Teachers annotate assignments with corrections and feedback. Learning enhanced through active markup.
Engineers mark up drawings with field notes. Technicians annotate manuals with tips. Site-specific information added directly to standard documents.
Fill in PDF forms by writing directly on the document. Check boxes by drawing, sign with signature tool, add dates and notes. Complete paperwork without printing.
ScanLens includes pen (for drawing, notes, and signatures), highlighter (semi-transparent for emphasis), seven colors (red, orange, yellow, green, blue, purple, black), and adjustable stroke widths from fine (2px) to bold (15px).
Yes, ScanLens fully supports Apple Pencil with pressure sensitivity and tilt recognition. Drawing feels natural and precise. Palm rejection ensures your hand resting on the screen doesn't create unwanted marks. Works with all Apple Pencil generations.
Yes, full undo/redo support lets you correct mistakes instantly. Tap undo to remove the last stroke, redo to bring it back. You can also clear all annotations and start fresh, or save multiple versions of annotated documents.
Yes, annotations are embedded in the PDF using standard formats. They appear correctly in Adobe Acrobat, Apple Preview, Chrome PDF viewer, and all other PDF readers. Recipients see your markups without needing ScanLens installed.
Yes, all annotation tools work with finger input. Use your finger to draw, highlight, and mark up documents. Zoom in for precision work. Apple Pencil enhances the experience but isn't required.
Download ScanLens free and start marking up documents. Pen, highlighter, multiple colors—all the tools you need for professional PDF annotation.