Before you start: signing 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.
The work is free; saving the finished file needs a licence. Run the whole job first, with your network tab open if you like — nothing about your document leaves this tab. $99 once, or $25 a week.
Draw it, photograph it or type it. Place it where it goes, and it becomes part of the page. $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.
What this actually does
- The signature becomes part of the page. It is drawn into the page’s content, not attached as an annotation on top of it. There is no object for a recipient to select, move or delete — deleting the annotations from a file signed this way removes nothing.
- Your signature never leaves your device. Neither does the document. That is the difference between this and every signing service that emails you a link.
- Your original file is untouched. PDFMod writes a new copy and hands it to you. The file you started from still says exactly what it said before, so it is on you to keep track of which copy is which.
- We show you a SHA-256 of the result. Keep it and you can prove later that a copy someone sends back is byte-for-byte the file you signed. It costs nothing and needs no account.
- Locking the form fields is all or nothing — and here is the one gap in it. If your PDF has fillable fields you can tick the box to freeze them, so what you signed is what the recipient sees. Some fields cannot be frozen safely — the usual PDF libraries paint over them and delete them anyway, which silently erases a tick box or two. PDFMod refuses before it starts if any field has nothing to draw, names that field, and afterwards refuses to hand you anything unless the finished document’s form comes back empty. Both of those read the form’s own list of fields, which is the honest limit of the claim: a fillable box that sits on a page while the form does not list it — malformed output some generators produce — is not on that list and can survive the flatten. It is rare, and we would rather tell you where to look than let you find out. If the file came from an unusual source, open the copy you are about to send and try to type in it.
What it is not
- It is not a digital signature. A flattened image of your handwriting is not a cryptographic certificate. A PAdES signature makes tampering detectable; this does not. Anyone claiming otherwise about a drawn signature is selling something.
- It is not tamper-proof. Flattening makes the signature not-trivially-removable, not impossible to remove. Someone with Acrobat Pro can edit page content.
- We will not tell you whether it is legally binding. That depends on your jurisdiction and the document. It is not our call to make.
- And it will sign a PDF that already carries one, after telling you what that costs. Flattening a mark into a cryptographically signed document voids that signature and nothing here can put it back. That is said at the drop zone and again beside the download — and then the work happens, because the consequence announces itself in a banner in every reader that checks, your original is untouched, and it is your document. Annotate says it in the same words.
Need something else? All of PDFMod’s tools work the same way: on your machine, and we never see your files.