PDFs were designed to be final. Unlike a Word file, a PDF does not hold paragraphs you can rewrite — it holds fixed marks at fixed coordinates. That is why "editing" a PDF almost never means what people expect, and why so many editors disappoint.
What every browser-based editor actually does, including this one, is draw a new layer on top of the existing page. You add text, shapes and images over what is already there. It is closer to annotating a printed sheet than to opening a document in Word.
Everything happens on your own device. The contracts, invoices and forms people mark up are rarely things you would hand to an unknown server, and here you do not have to.
What You Can Do
Tool
Typical use
Text
Filling a field, adding a note, correcting a detail by covering it and typing over
Rectangle
Whiting out an error, framing a section, boxing a total
Circle
Ringing a figure or a clause that needs attention
Arrow
Pointing at what you are commenting on
Highlighter
Marking passages for review without obscuring them
Image
Dropping in a logo, a stamp, or a signature graphic
The colour picker applies to whichever tool is active, and anything you place can be selected, moved, resized or deleted before you save.
Covering text does not remove it. A white rectangle over a figure hides it visually, but the original characters are still in the file and can be selected, copied or recovered. If the point is to eliminate confidential content, use Redact PDF instead — and read why a black box is not redaction first. This is the single most consequential misunderstanding about PDF editing.
Picking the Right Tool for the Job
Most of the time, a different tool does the job better than a general editor:
Rewriting existing body text. Not really possible on a PDF. Convert it with PDF to Word, edit properly in a word processor, then convert back.
Removing sensitive content.Redact PDF — it deletes rather than covers.
If the page is a scan, there is no text underneath at all — just an image. You can still draw on top, but nothing is selectable. Run OCR first if you need the words to be searchable.
Frequently Asked Questions
Is my PDF uploaded anywhere?
No. The document is opened and edited entirely in your browser, and the saved file is generated on your device. Nothing is transmitted.
Can I edit the existing text in the PDF?
Not directly. A PDF stores fixed marks, not editable paragraphs. You can cover text and type over it, or convert to Word, edit there, and convert back for a proper rewrite.
If I cover text with a white box, is it gone?
No. It is hidden but still present in the file and recoverable. Use Redact PDF to actually delete it.
Why can I not select the words on my page?
The page is almost certainly a scan — an image of text rather than text. Run OCR to generate a searchable text layer.
Can I add my signature or a company logo?
Yes, with the image tool. For signing specifically, Sign PDF is the better fit, and PDF Overlay applies a logo across every page at once.
Will my edits be editable again later?
No. Once saved, added text and shapes are drawn into the page like any other PDF content. Keep your original if you may need to revise.