# Annotate PDF

> Annotate PDF lets you mark up documents with text highlights, sticky-note comments, freehand pen drawings, rectangles, lines, and ellipses right in your browser. Sticky notes are saved as real PDF comment annotations, while visual marks are drawn into the page. Files stay on your device, with no upload, account, or watermark.

**Canonical:** https://trydocsy.com/pdf/annotate
**Last updated:** 2026-10-31
**Privacy:** Runs in your browser; the file is never uploaded.

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Reviewing contracts, academic papers, and project plans means making clear marks on the page. Annotate PDF puts those tools in your browser: the pen is ready as soon as your file opens, so you can sketch notes, frame a figure with a shape, or highlight a line of text.

Everything runs in your browser, so private records stay on your device. A mark drawn over text doesn't remove that text. To take it out of the file, use [Redact PDF](https://trydocsy.com/pdf/redact). If you need to revise underlying sentences or correct typographical errors, see [what it takes to change PDF text](https://trydocsy.com/blog/how-to-edit-a-pdf) or switch to [Edit PDF](https://trydocsy.com/pdf/edit). To sign, open [Sign PDF](https://trydocsy.com/pdf/sign), or use [Make PDF Fillable](https://trydocsy.com/pdf/make-fillable) to add text fields and checkboxes.

## How it works

1. **Open your PDF file** — Select your PDF from local disk storage or drag the file into the markup workspace. The document opens immediately in client memory.
2. **Choose an annotation tool** — The pen is active when your file opens. Pick Draw rectangle, Draw line, or Draw ellipse from the toolbar to change it, and choose a color and width.
3. **Draw, then mark text** — Draw on the page. To mark text, choose Select / move, click a line, and pick Highlight, Underline, or Strikethrough in the side panel. The mark covers that whole text fragment.
4. **Export your annotated document** — Check your pages, click Download in the top bar, and save the updated PDF.

## When you'd use it

- **Legal contract review and clause examination** — Tint disputed clauses with yellow highlights and draw red border boxes around liability terms during team contract negotiations.
- **Grading student essays and coursework papers** — Sketch correction marks with the pen, strike through a wrong line, and underline key sentences on student submissions.
- **Architectural blueprint and schematic callouts** — Draw precise ellipses around design discrepancies and add connector lines to highlight specific dimension errors on building plan sheets.
- **Study notes on scientific research articles** — Highlight methodology summaries in journal articles and draw boxed margins around critical data tables for rapid revision before exams.

## How are annotations saved into the PDF file?

TryDocsy supports two distinct types of markup: marks drawn into the page, and PDF comments.

Highlights, pen drawings, rectangles, lines, and ellipses are drawn directly into page content as ordinary PDF graphics. Highlights are semi-transparent color bands over the original text, and shapes and ink are vector paths. Because these marks are part of the page content, they show in any viewer without comment support and print cleanly.

Sticky notes are saved as PDF /Subtype /Text comment annotations with a unique ID, a timestamp and an appearance. They are designed to show in a reader's comments list, but they are not tested in Acrobat or Preview: we read them back with pdf.js only. This tool does not make threaded replies. For form fields, use [Make PDF Fillable](https://trydocsy.com/pdf/make-fillable).

## What annotation tools and styling options are available?

The toolbar includes drawing tools, text marking tools, and a sticky note comment tool. The pen follows your cursor or stylus for handwriting, checkmarks, and margin sketches. Text marks cover whole text fragments with highlights, underlines, or strikethroughs.

The sticky note tool lets you tap or click anywhere on a page to place a comment note up to 10,000 characters, with an optional author name. Drawing tools offer five colors (red, black, blue, green, and yellow) and three widths (thin, medium, and thick). Until you download, a note can be moved, edited, or deleted, and a shape can be moved or deleted but not resized.

## What markup capabilities were tested on synthetic documents?

We drew marks and placed sticky-note comments on a synthetic PDF using Microsoft Edge 156 on Windows 11, downloaded the file, and verified the structure.

We verified saved bytes and annotations with pdf.js and pdf-lib. Note that these files were not tested in Acrobat or Preview, so verify the result in your preferred reader before distributing sensitive documents.

*Markup rendering checks on synthetic documents, Microsoft Edge 156 on Windows 11, 2026-10-31*

| Mark | How it's stored | Page text after download | Comment annotations in the file |
|---|---|---|---|
| Sticky note comment | /Subtype /Text annotation | Unchanged | 1 per note |
| Text highlight | Semi-transparent band | Unchanged | None |
| Freehand pen | Vector path | Unchanged | None |
| Rectangle and ellipse | Vector outline | Unchanged | None |
| Straight line | Vector line | Unchanged | None |

## Frequently asked questions

**Q: Can other people delete or remove my annotations in another PDF reader?**
A: A sticky note is a comment, so a reader that supports comments should let people change or delete it. Drawing marks and highlights are in the page itself, so they aren't comments, though a full PDF editor can still change page graphics. Don't rely on either to protect anything.

**Q: Does this tool support sticky notes or text comment bubbles?**
A: Yes. You can place sticky-note comments (/Subtype /Text annotations) anywhere on the page, type up to 10,000 characters, and add an optional author name. They are stored as comments, not tested in Acrobat or Preview, so check one in your reader first. Drawing marks and highlights remain drawn into the page graphics.

**Q: Can I annotate a PDF on a tablet or touchscreen device?**
A: The pen is built on browser pointer input, which covers touch and stylus as well as a mouse. We have tested it with a mouse in Edge on Windows only, so try a short stroke on your device first.

**Q: Will highlighting text obscure or blur the words underneath?**
A: No. A highlight is a semi-transparent color band over the text, so the words stay readable through the tint.

**Q: How can I remove an annotation before downloading the file?**
A: With Select / move active, click a shape or pen stroke and press the Delete key. You can also press Ctrl+Z or Cmd+Z to undo recent marks. To clear a text mark, select the line and click the same mark again.

## Step-by-step guides using this tool

- [How to Add a Hyperlink to a PDF: 4 Methods](https://trydocsy.com/blog/add-link-to-pdf)
- [How to Annotate a PDF for Free: 4 Methods](https://trydocsy.com/blog/how-to-annotate-a-pdf)

## Related tools

- [Edit PDF](https://trydocsy.com/pdf/edit)
- [Redact PDF](https://trydocsy.com/pdf/redact)
- [Sign PDF](https://trydocsy.com/pdf/sign)
- [Make PDF Fillable](https://trydocsy.com/pdf/make-fillable)
- [Add Link to PDF](https://trydocsy.com/pdf/add-link)

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## About TryDocsy

TryDocsy is a free website of PDF, image and file-conversion tools that run entirely in your web browser, so your files are processed on your own device and never uploaded. It also includes photo and signature resizers preset to Indian government-exam specifications.

- Website: https://trydocsy.com
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- Contact: https://trydocsy.com/contact