Annotate PDF
Legal redlines. Contract reviews. Medical record markup.
Some PDFs shouldn't leave your device. Annotate them in your browser — nothing uploads.
Press Ctrl/Cmd-Z to undo. Use arrow keys to nudge a selected annotation. Tab cycles through annotations on the current page. Page Up / Page Down navigates pages.
PDF annotated — {count} annotation(s) on {pages} page(s)
Success
Your annotations are embedded into the PDF. Download below.
PDF annotated — {count} annotation(s), with notes
Success with notes
Annotation completed. See the notes below for details about non-Latin text fallback.
Annotation notes
Need reversible annotations?
Drawn annotations bake into the page appearance — they look identical to interactive annotations but cannot be moved or removed by the recipient. For reversible annotations that recipients can edit, use Adobe Reader, Foxit, or Preview.app — those tools support interactive annotations stored as /Annot PDF dictionary entries.
About annotating PDFs
What this tool annotates
Three annotation types: highlight (yellow rectangle over any region), freehand draw (pencil-style strokes), and text annotation (typed text overlay). Annotations bake into the PDF page appearance — visually faithful but not removable in Adobe Reader. For reversible annotations that recipients can edit, see the FAQ below for the alternative.
When to use it
Legal contract redlines, document review markup, medical record annotations, draft policy review, classroom PDF markup — anything where annotation data and source PDF are sensitive enough that uploading to a third-party converter is the wrong shape.
Privacy framing
Per empirical research, every reachable PDF-editor competitor (Smallpdf, iLovePDF, PDFCandy, Sejda, PDF24) processes content on their servers or with ambiguous "browser-based" framing involving an upload step. Adobe Acrobat fill-and-sign paywalls the feature. The browser-only privacy quadrant is unoccupied. Annotate PDF runs entirely on your device — source PDF and your annotations stay in your browser.
What we don't handle and why
Annotations are drawn-content (baked into the page), not reversible /Annot dictionary entries — pdf-lib v1.17's public API only supports drawn-content. For reversible annotations, route to Adobe Reader, Foxit, or Preview.app via the FAQ below. Text annotations use Helvetica WinAnsi — non-Latin characters (Cyrillic, Arabic, CJK) replace with "?" and surface a fallback warning. Pages with rotation metadata are supported (worker handles rotation transform automatically).
Workflow chain
After annotating, add a password before sharing with Protect PDF. If the source PDF is encrypted, remove the password in your PDF software first. If the source PDF is damaged, repair it first via Repair PDF.
Frequently asked questions
- What can I annotate?
- Three annotation types in v1: highlight (yellow rectangle over any region), freehand draw (pencil-style strokes), and text annotation (typed text overlay). All three available without sign-up.
- Will my annotations be removable later?
- No. Drawn annotations bake into the page appearance — they look identical to interactive annotations but cannot be moved or removed by the recipient. For reversible annotations that recipients can edit, use Adobe Reader, Foxit, or Preview.app — those tools support interactive annotations stored as /Annot PDF dictionary entries. This is the trade-off for browser-only processing with the public pdf-lib API only.
- What kinds of PDFs can I annotate?
- Most standard PDFs work. Encrypted PDFs need the password removed first (in your PDF software). Damaged PDFs need to be repaired first (Repair PDF tool). Pages with rotation metadata are supported automatically. Text annotation uses Helvetica WinAnsi — non-Latin characters (Cyrillic, Arabic, CJK) replace with "?" and surface a fallback warning.
- Are my PDFs uploaded to your servers?
- No. All annotation runs in your browser via pdf-lib. Source PDF and your annotations never leave your device. We have no servers receiving the content.
- Can I undo my annotations?
- Yes — up to 50 actions across all pages. Ctrl/Cmd-Z keyboard shortcut for undo, Ctrl-Shift-Z / Cmd-Shift-Z (or Ctrl-Y on Windows) for redo. Cross-page undo is supported (undoing on page 2 reaches actions made on page 1). There's no separate erase tool — undo IS the erase mechanism, which avoids tool-mode confusion.
- Does it work on touchscreens?
- Yes. Pointer Events API handles tap and drag on modern mobile browsers. iOS Safari before 13 falls back to Touch Events.