Tool category

Protect and sign PDF files

You can protect PDF files, unlock PDF passwords, sign PDFs, add certificate security, or apply watermarks, bates numbers, and page numbers before you share. This category groups every finishing tool you need to protect PDF documents — password protection for private recipients, unlock for PDFs you already hold a password for, certificate signing for auditable delivery, and preflight validation for accessibility or archival handoff. Your protected files are built in the browser, and no hidden account or hosted queue is required. When you still need to edit, compress, or convert first, the related tool links keep the next step close.

ISO/IEC 27001 (in progress)
GDPR compliant
TLS 1.3
Files deleted after 1 hour
No signup required

Protect and prepare tools

Lock down finished PDFs or add numbering before the final export.

Frequently asked questions

Category-specific answers so you can pick the right tool before you upload. Tap any question and the answer expands inline.

How do I password-protect a PDF?
Upload the file to the protect PDF tool, set a password plus optional printing or copying rules, and download the locked copy. Your PDF is encrypted on export — recipients need the password you set to open it.
Can I unlock a PDF I already have the password for?
Yes. The unlock PDF tool takes the password you already hold and removes encryption locally so you can keep working. Pdf Clarity cannot bypass a password you don't know, and unsupported encryption methods are called out instead of silently failing.
Is it safe to sign a PDF online?
Yes. Your signatures apply in the browser — you don't upload to a hosted queue. For audit-grade delivery, the certificate security tool uses your own digital ID and stamps the signed PDF so recipients can verify it after download.

Related guides

PDF editor comparisonsSee how Pdf Clarity compares to Adobe Acrobat, Smallpdf, Sejda, iLovePDF, and Canva before you commit.PricingSee what stays free and where the paid tier starts, so you can plan your PDF work.TrustSee how we handle your files — encrypted uploads, deleted within the hour, never shared.