How to Annotate PDF Documents: 14 Tools, One Group
The Annotate group of the Utilvo Advanced PDF Editor ships with 14 tools for marking up an existing PDF without touching its text content. Highlights, sticky notes, free-draw ink, geometric shapes, stamps, links, embedded images, and callouts — all rendered as standard PDF annotation objects and preserved exactly when you export.
Open the editor, drop your PDF, and follow the steps below.
Why Annotate a PDF Instead of Editing the Text?
Annotations are overlay objects — they do not modify the underlying text. According to the PDF specification (ISO 32000), annotations are stored in a page's /Annots array separately from the content stream, which makes them ideal for:
- Legal review — redlines and counter-proposals without rewriting the original.
- Academic reading — highlights and margin notes for a thesis or research paper.
- Editorial collaboration — proof marks for a manuscript that the typesetter will resolve.
- QA review — sticky-note comments tied to specific coordinates of a UI mockup.
The 14 Annotate Tools at a Glance
The Annotate group is the first tab in the toolbar and the one you'll use most. Every tool is click-to-place — pick a tool, click on the page, and the annotation appears at your cursor.
Pick, move, resize, or delete any annotation. Press Esc to deselect.
Pan around the page when zoomed in. Hold Space for temporary pan mode.
Drop a text box anywhere on the page. See the dedicated Text guide for typography details.
Drag over text to highlight. Choose yellow, green, pink, or blue from the settings panel.
Highlight by freehand — draw across multiple lines or non-rectangular regions.
Draw a horizontal line through selected text. Standard editorial redline.
Draw a horizontal line under selected text. Pairs with Strikeout for editorial marks.
Freehand ink with pen smoothing. Configurable stroke width and color.
Click on any annotation to delete it. Drag to lasso multiple annotations.
Opaque white rectangle. Use to cover text before overlaying new content with the Text tool.
Drop a yellow square that opens into a text editor. Stored as /Text annotation.
Embed a PNG/JPG/SVG image anywhere on the page. Supports rotation and resize.
Text box with a tail pointing at content. For pointing at specific clauses or figures.
Draw a rectangle hotspot that links to a URL, internal page, or email.
A note on Shapes and Marks
Two adjacent groups cover related ground: Shapes has Rectangle, Circle, Line, Arrow, and Table — for when you need crisp geometry rather than freehand ink. Marks has Check, Cross, Dot, Redact, Watermark, Stamp, and OCR Scan — for explicit status indicators and bulk operations. All three groups share the same click-to-place convention, so the muscle memory transfers.
Heads up: The Annotate group has a Whiteout tool for covering content, but Redact (in Marks) is a permanent-looking black overlay for hiding PII. See the Security guide for the full comparison.
Highlight
Drag the cursor over any word, phrase, or paragraph to highlight it. The highlight is stored as a /Highlight annotation under the page, with a customizable color (default yellow) and opacity. Use this for textbook study, contract review, or surfacing important clauses.
Open the tool's settings panel to switch between yellow (terms), green (agreed clauses), pink (objections), and blue (questions). The same color-coding convention used in legal practice.
Sticky Note
Click anywhere on the page to drop a sticky note icon. Click the icon to open the note editor and type your comment. Notes are stored as /Text annotations, which appear in the Acrobat comment list and are exportable as FDF.
Pen (Free Draw)
The Pen tool captures hand-drawn ink strokes — perfect for circling, underlining by hand, or sketching quick diagrams on top of a screenshot. Stroke width is configurable (0.5 to 8 pt), and pen smoothing runs at every pointer move so even a shaky trackpad trace comes out clean.
For an irregular region — a paragraph that wraps, an image with a curved edge, a chart with non-axis-aligned data — the Pen is faster than drawing a Rectangle. The ink is also more readable for circled, arrowed, and underlined marginalia than a stamped shape.
Geometric Shapes
Switch to the Shapes tab to access Rectangle, Circle, Line, Arrow, and Table. Each tool is a click-and-drag placement — start at one corner, drag to the opposite corner, release to commit. Stroke and fill colors are set in the context toolbar that appears after placement.
Stamps
The Stamp modal opens with twelve presets: Approved, Completed, Received, Final, Confidential, Draft, Void, Rejected, Paid, For Review, Urgent, and Copy. Each preset renders as a red oval stamp. Click a preset, click on the page, and the stamp appears at your cursor. Stored as /Stamp annotations; searchable by text in compliant viewers.
Links
The Link tool draws a rectangular hotspot on the page and lets you bind it to one of three target types: an external URL (https://utilvo.com), an internal page jump (Page 4 of the current document), or an email (mailto:[email protected]). Stored as /Link annotations and rendered with a thin blue border on hover.
Common Workflow — Reviewing a Contract
A typical review session combines several tools. Here's a five-step flow that mirrors how lawyers and editors actually mark up PDFs:
- Skim first with Highlight. Drag a yellow highlight over every clause that warrants a closer read. Yellow = "look here."
- Switch color when the meaning changes. Green for "agreed as written," pink for "object," blue for "question for opposing counsel."
- Attach a Sticky Note to each flagged clause. Click the paragraph, then click the sticky-note icon that drops. Type the rationale in the editor.
- Use Strikeout + Text for redlines. Strikeout the original wording, then drop a Text annotation with the proposed replacement directly under it.
- Sign the cover page. Switch to the Signature tab and stamp or sign the cover page after review is complete.
What annotations can and cannot do
- • Annotations are always preserved through Utilvo's export — they are written into the PDF's /Annots array, not flattened by default.
- • To "burn in" annotations (merge them into the page so they cannot be removed), use the Flatten option in the Download modal.
- • The Eraser tool only removes annotations from Utilvo's in-memory state. If the PDF was opened with annotations already present, those are not editable through Utilvo's Eraser; use the Security group's Redact for permanent-looking removals instead.
Further Reading
- Wikipedia — Portable Document Format— annotation model and PDF object dictionary.
- Wikipedia — Xournal— open-source reference for free-draw PDF markup.
- Wikipedia — Proofreading— the editorial tradition of markup and tracked corrections that the Strikeout + Text pattern continues.
Frequently Asked Questions
What annotation types are supported?
Highlight, sticky note, free-draw, shape (rectangle, ellipse, line, arrow), text callout, stamp, link, table, and image. Each tool is fully configurable for color, opacity, and stroke width.
Are annotations preserved when recipients open the file?
Yes. All annotations are written as PDF-native objects (annotation dictionaries under each page) so they render in Acrobat, Foxit, Preview and Chrome exactly as you placed them.
Can I delete an annotation after placing it?
Click the annotation to reveal a delete handle (red ×) and a Move button. The annotation can be dragged to reposition or removed with a single click.
Do annotations count as edits to the original text?
No. Annotations are overlay graphics — the underlying text remains untouched, which is essential for legal review and academic commenting workflows.
Continue to the Next Group
Next up: the Forms group — AcroForm fields, click-to-place, and fillable PDF creation.
Read: Create Fillable PDF Forms