Highlight important areas of a PDF
The highlight tool can be used for reading and review. Use it to mark a clause in a contract draft, a paragraph in a report, a line in study notes, or an instruction in a manual. Opacity and colour controls let you keep the underlying page visible instead of covering it with a solid block.
Underline or strike through material
Underlining can draw attention to a line without flooding the area with colour. Strikeout comes in handy on review copies when a word, phrase, or section should be removed or reconsidered.
Draw freehand on PDF pages
Freehand pen markup is done in a much faster way, since it draws than types, and can be useful to circle a number, point an arrow at a problem, sketch a quick correction, or jot a handwritten note. On a touchscreen or pen-enabled device, it can resemble a marking paper. On desktop, a mouse or trackpad works fine for simple strokes.
Add rectangles and ellipses
Shapes are especially handy for screenshots, diagrams, plans, forms and dense pages where a highlight does not clearly identify the intended area. Draw a rectangle around a field that needs attention or an ellipse around a number, date or visual element.
Markup versus adding text and signatures
If you need to type a name onto a form or place a signature, use Edit & Sign PDF. If you are commenting on the document visually: highlighting, underlining, drawing or adding shapes, use Markup. Keeping those jobs separate makes both interfaces more distinctive.
Why annotate a PDF locally in the browser?
Review copies can also be of a sensitive nature. A draft contract, internal report, manuscript, client document, or marked-up form may contain material you’d rather not send to a remote processing service. WhatPDF Online is designed so supported markup operations happen right in the browser, rather than by deliberately uploading the document contents to UsefulKits for annotation.
Keep the original if the markup matters
Markup can be useful evidence of a review process, but it can also make a clean document harder to recover if you overwrite your only copy. WhatPDF exports a new marked PDF; keep the original clean version until you know the annotated version is the one you want to circulate.
Frequently Asked Questions
Can I highlight a PDF online?
Yes. WhatPDF Online includes visual highlighting along with underline and strikeout markup.
Can I draw on a PDF?
Yes. The free Markup workspace includes a freehand pen plus rectangle and ellipse shapes.
Can I use markup to redact private information?
No. Visual markup should not be treated as secure redaction because the original underlying content may remain recoverable.
Does WhatPDF add a watermark to my markup?
The WhatPDF Online markup workflow is designed to export the marked document without adding a promotional watermark.