Before you start: marking up a file is free and needs no account. A PDFMod licence is what saves the finished file — $99 once for the whole toolkit, or $25 for a week.
Highlight a clause, circle a figure, leave a note. $99 once and the whole toolkit is yours — Acrobat is about $155 a year and stops the day you stop paying. We never see the document either: this page is not permitted to open a connection to anywhere else, and you can watch that in your browser’s network tab.
How the marks behave
- Marks are drawn into the page, not stuck on top of it. They are page content, the way a printed-and-scanned markup would be — not PDF annotations a recipient’s reader can hide or strip in one click.
- Highlights let the words through. They use a multiply blend rather than a translucent block, so text under a highlight stays as readable as it was, and stays selectable and searchable.
- Rotated pages work. A page saved sideways is the classic way markup tools land ink in the wrong place, or upside down. Placement here was checked corner-by-corner at every rotation, on pages whose crop box doesn’t start at the origin.
- Undo means the last mark you made, not the last one on this page. If it was three pages back, the view follows it there so you can see it go — a button that appears to do nothing is worse than one that scrolls. Clear this page is the separate, per-page eraser.
- Your original file is untouched. PDFMod writes a new copy. Once you download it the marks are part of the page and this tool cannot take them off again — go back to your original if you need a clean one.
Three limits worth knowing
- Notes are set in Helvetica. Every PDF reader already has it, so nothing is downloaded and no font is embedded in your file. The trade is that it covers Latin characters only. Type something outside that and the note still goes on the page: PDFMod writes the closest thing the font really holds — “fi” as “fi”, “José” as “Jose” — and tells you, character by character, what it changed. What it will never do is quietly write a question mark into a file you then send to somebody.
- Highlighting is a rectangle you drag, not a text selection. It works the same on a scan as on a text PDF, which is the point — but it will not snap to a line of type for you.
- A digitally signed PDF is marked up, and told on you. Drawing into the page voids the certificate and nothing here can put that back, so PDFMod says so at the drop zone and again beside the download. Then it does the work: the consequence is a banner in every reader that checks signatures, your original is untouched, and it is your document to decide about. Sign says it in the same words.
Looking to hide something rather than point at it? Highlighting and boxes are markup, not redaction — a black box drawn over a word leaves the word in the file, fully recoverable. Use Redact for that, which removes the content and proves it before letting you download.
All of PDFMod’s tools work the same way: on your machine, and we never see your files.