🖊️Annotate PDF Online - Highlight, Draw, Add Notes & Text
Reviewing a contract, marking up a thesis or grading homework means highlighting passages, circling problems and leaving comments on a PDF. This tool shows the PDF page by page with a toolbar of annotation tools: highlight (multiply blend, so the text underneath stays readable), freehand pen, rectangle, ellipse, line, arrow, sticky note and text box. Each tool has its own colour, line width and opacity, and text boxes have a font size; with the select tool you can click an annotation to select and drag it, press Delete to remove it and Ctrl/⌘+Z to undo. Sticky notes and text boxes accept any language, including Chinese. You can save in two ways. “Standard annotations” writes real PDF annotation objects (Highlight, Ink, Square, Circle, Line, Text and FreeText) that appear in the comments list of Adobe Acrobat, macOS Preview, Edge and Chrome, where they can still be edited, replied to or deleted, with an optional author name. “Merge into the page” draws the annotations into the page content so they look the same in every reader and on paper, with sticky notes expanded into small text boxes. Rotated pages are handled correctly, the original text and images are untouched, and everything runs locally in your browser.
Free · No sign-up · Runs in your browserLast updated:
How to use Annotate PDF
- 1Upload the PDF to annotate; switch pages from the thumbnail strip
- 2Pick highlight, pen, a shape, sticky note or text box and drag or click on the page; adjust colour, width and opacity, and use the select tool to move or delete annotations
- 3Choose standard annotations or merge into the page, then click Save & download
FAQ
- What is the difference between standard annotations and merging into the page?
- Standard annotations are separate objects that show up in the comments panel of Acrobat, Preview and other readers, where they can be edited, replied to, hidden or deleted. Merging draws them into the page content, so they look identical everywhere and when printed but can no longer be edited individually. Use the first for review, the second for final copies.
- Will the highlight cover the text?
- No. Highlights use the multiply blend mode at 45% opacity by default, so the text underneath stays crisp and can still be selected and searched.
- Can sticky notes and text boxes contain Chinese or other scripts?
- Yes. Note text is stored as Unicode in the annotation, so any language displays correctly. A text box’s appearance on the page is drawn as a high-resolution image, so CJK characters never turn into boxes, and the original text is also kept in the annotation contents.
- Are my files uploaded?
- No. Page previews, drawing and saving the PDF all happen in your browser with no network upload, and everything is discarded when you close the page.