How to sign a PDF online for free
- Open the signing tool and drop in your PDF (or tap to choose it).
- Create a signature: draw it with a mouse, trackpad or finger, type your name in a handwriting-style font, or upload an image of your signature.
- Drag the signature onto the page and resize it. Add initials, a date stamp or a text field (for your name or title) wherever you need them, on any page.
- Click Finalize & export. You get a signed PDF with a completion certificate page and a SHA-256 tamper seal, saved straight to your device.
What "no upload" means here
Your browser reads the file with its built-in File API. Pages are drawn with pdf.js, the signed copy is written with pdf-lib, and the hash is computed by the browser's own WebCrypto. None of these steps needs a server. You can test it: load the page, switch off Wi-Fi or mobile data, and sign. It still works.
What's free
Signing, sealing and verifying are free, with no document limit and no sign-up. Your pages are not watermarked; the free plan only adds a small "Signed privately with OpenSigner" line, linking to the verifier, on the completion certificate page. Pro is optional and is for people who want their own logo on that certificate.
When this is the right tool
It suits signing a document yourself: an offer letter, a rental agreement, a consent form, an NDA or a school form. If you need to send a document to several people and track who has signed, a hosted workflow service is a better fit (see our DocuSign comparison).