Sign a PDF in your browser without uploading it

The documents people sign are leases, offer letters, consent forms and agreements, and the signed version is the one that binds. It contains the terms, the parties, the amounts and your signature, which is a reusable image of your own hand. Every service that receives it holds all of that together in one file.

Be clear about what this produces. A drawn, typed or uploaded signature is a mark on the page. It is what most everyday paperwork asks for and it is widely accepted in ordinary business, but it carries no cryptographic proof of who applied it and no evidence that the file is unchanged since. If a counterparty asks for a signature their software can validate against a certificate, this is not that, and saying so is more useful than letting you find out later.

Treat the signature image itself as an asset worth protecting. Once it exists as a file, it can be lifted and placed on any document by anyone who has it, which is true of scanned signatures too. Signing locally means the only copies are the ones you made, and there is no third party holding a clean cut-out of your name.

To check the claim, open the network panel, place the signature, and watch that neither the document nor the signature image is transmitted. Better still, disconnect first: drawing a signature and stamping it onto a page is arithmetic on your own machine and it completes offline.