Edit the text that's already in your PDF: click any line, in Arabic or English, and type. The font size, style and colour are matched, and the old words are removed from the file, not just hidden. You can also add new text, signatures and stamps, white-out, highlight, and draw boxes, arrows or freehand notes.
Yes. Click the line and type, just like in a word processor. When you save, the original words are taken out of the page and your new text is written in their place, so the old text can't be copied or found by search afterwards.
It matches the size, weight, style and colour, and uses the closest standard font (sans-serif, serif or monospace). English text is saved as real, selectable text; Arabic is drawn with a proper Arabic font so the letters join correctly.
A scanned page is a photo of text, so there are no letters to edit. Make it searchable first, or cover the words with White-out and type over them with Text.
No. It hides the words on screen and in print, but the original text stays inside the file and can still be copied or found by search. To share a document safely without the hidden text, print it to PDF or use PDF to JPG and then Images to PDF.
Everything happens in your browser. Your files are never uploaded to a server, so nobody else can see them.