# Annotate and highlight a PDF online

> Add highlight, underline, strikethrough, text, arrows, shapes and stamps to a PDF. Marks snap to text lines. Runs in your browser, no upload.

Marking key points, adding notes and circling problems takes only a few tools. Highlight, underline and strikethrough snap to text lines, and every mark is drawn in your browser.

URL: https://pdf.qilingtools.com/en/annotate-pdf
Other language: https://pdf.qilingtools.com/zh/annotate-pdf

## How it works

1. **Open the PDF** Choose a file or drop a PDF onto the page.
2. **Pick an annotation tool** The toolbar has highlight, underline, strikethrough, text, rectangle, ellipse, line, arrow and pen, plus check, cross and date stamps.
3. **Mark up the page** Drag across text to snap to the text lines, or click to take a whole line; draw the other shapes by dragging. Selected marks can change color, width and opacity, and resize from the corners.
4. **Export** Click "Export PDF" and all annotations are drawn into the new file.

## Good to know

- Undo and redo any time (⌘/Ctrl+Z); a selected mark can be copied, brought to front or deleted.
- A cover box hides content with a colored block, but the original stays in the file underneath, so it is not secure redaction.
- Annotations are drawn onto the page rather than stored as PDF annotation objects, so they show up in any PDF reader.

## FAQ

### How do I highlight text in a PDF?

Choose the Highlight tool and drag across the text; the highlight snaps to the text lines. A single click selects a whole line.

### Will my annotations show in other PDF readers?

Yes. They are drawn into the exported pages, so any PDF reader shows them.

## More things you can do

- [PDF editor home](https://pdf.qilingtools.com/en)
- [Edit PDF text](https://pdf.qilingtools.com/en/edit-pdf-text)
- [Sign a PDF](https://pdf.qilingtools.com/en/sign-pdf)
- [Merge PDFs](https://pdf.qilingtools.com/en/merge-pdf)
- [Split a PDF](https://pdf.qilingtools.com/en/split-pdf)
- [Reorder & rotate pages](https://pdf.qilingtools.com/en/reorder-pdf-pages)
- [Add page numbers](https://pdf.qilingtools.com/en/add-page-numbers)
- [Fill in PDF forms](https://pdf.qilingtools.com/en/fill-pdf-form)
- [Add an image](https://pdf.qilingtools.com/en/add-image-to-pdf)