Frustrated with "signature invalid" errors? Certificate problems? Signatures that don't work across devices? You're not alone. Here's why it happens and how SignItPDF fixes these issues.
This error appears when Adobe Acrobat can't verify the signature certificate or detects document modifications.
Your signature shows as invalid across different PDF viewers or when others open the document.
PDF viewers don't recognize or trust the certificate used to create your signature.
Even minor changes to the PDF after signing can invalidate all signatures in the document.
Traditional PDF signing relies on digital certificates that must be properly installed, trusted, and maintained across all devices and PDF viewers. When certificates expire, are revoked, or aren't recognized by different software, signatures fail.
A signature that works in Adobe Acrobat might fail in other PDF viewers. Different software handles certificates and validation differently, leading to inconsistent results across devices and applications.
PDF signatures are extremely sensitive to any document changes. Even automatic optimizations by email systems or cloud storage can invalidate signatures, making documents appear tampered with.
Many online PDF signers upload your documents to their servers, introducing additional points of failure, security risks, and potential document modifications that can break signature validation.
Your documents never leave your device. All signing happens locally in your browser, eliminating server-side risks and ensuring document integrity.
SignItPDF creates signatures that work consistently across all PDF viewers, devices, and platforms without certificate dependencies.
Skip the complexity of certificate management. Our signatures are embedded directly into the PDF without relying on external certificate validation.
Our signatures remain valid even when documents are compressed, emailed, or processed by various systems, providing reliable long-term validity.
Stop wasting time with signatures that don't work. Try SignItPDF and experience reliable, error-free PDF signing that works every time, on every device.
Sign Your PDF Now