Guides & tips for working with PDFs
Practical how-tos, behind-the-scenes notes, and product updates from the team behind Blackpdf.
Security & signing
Password protection, redaction, encryption, and signatures.
Security & signing
Password protection, redaction, encryption, and signatures.
How PDF Encryption Works (And When It's Not Enough)
What PDF passwords actually protect, user vs owner passwords, why older PDFs are crackable, and when you need more than a password.
Digital Signature vs Electronic Signature
Electronic, digital, and e-signature get used interchangeably but they're different. Here's what each term actually means, legally and technically.
How to Redact a PDF (Hide Sensitive Information)
Permanently redact sensitive content from a PDF: manual marking, find-and-redact text search, or auto-detect for emails, phones, and SSNs. Step-by-step guide.
How to Unlock a PDF (Remove Password Protection)
Remove password protection from a PDF you have the password for. Step-by-step guide, plus what to do if you've forgotten the password.
How to Password-Protect a PDF
Add a password to a PDF so only people with the password can open it. Step-by-step guide, plus how to pick a strong password and what to do if you forget it.
How to Sign a PDF Online
Add a signature to a PDF online: draw it, type it, or upload an image. Step-by-step guide, plus how to lock the signature so it can't be moved.