About this tool

FirmaLocal is a web tool for signing PDFs with a Spanish digital certificate (FNMT, ACCV… as a .p12 or .pfx file) without installing Autofirma, Java or anything else. The PAdES-B-B signature is computed in your browser: the PDF, the certificate and its password never leave your device, as you can check in the DevTools Network tab. Works in Chrome, Edge, Firefox and Safari on Windows, macOS, Linux, Android and iOS. No sign-up, no signature limit, plus 60+ guides to fixing Autofirma errors.