Password Protect PDF
Encrypt a PDF with AES-256, the current standard. The password is used once and never stored — by anyone.
Encrypted, not just hidden
There is a difference between a password prompt and encryption. A prompt can be skipped by any tool that chooses not to show it; encryption makes the document's bytes unreadable without the key. This tool does the second: AES-256 under PDF security revision 6, which is what the PDF standard currently specifies and what Acrobat, Preview, browsers and phones all expect.
The honest consequence: a forgotten password means a lost document. Nobody — including us — can recover it, which is precisely the guarantee encryption is supposed to make. That is why the form asks for the password twice.
When to lock a PDF
Payslips and contracts sent over email, a document headed to a shared drive, an attachment that will outlive the conversation it was sent in — anything where the file will travel beyond your control is a candidate. Send the password through a different channel than the file: the lock is only as good as that separation.
Changed your mind later? Remove the password with the matching tool — as long as you know it. And since locked files cannot be processed, do any merging or compressing first, and protect the final version.
About Protect PDF
Put a password on a PDF before you send it. The file is encrypted with AES-256 — the same standard banks and governments specify, and what every modern PDF reader expects — so the document is unreadable without the password, not merely hidden behind a prompt. The password you type is used once to encrypt the file and is never stored or logged; if you lose it, nobody, including us, can get the document back, which is exactly the guarantee you are buying.
- AES-256 encryption (PDF 2.0, security revision 6) — the current standard, not legacy RC4
- Opens in every modern reader: Acrobat, Preview, browsers, phones
- The password is used once and never stored, logged or recoverable
- Passwords from 4 to 128 characters — longer is stronger
- Document metadata is kept intact: protecting a file should not alter it
Frequently asked questions
- How do I put a password on a PDF?
- Upload the file, type the password twice, and download the protected copy. Anyone opening it — in Acrobat, a browser, or on a phone — is asked for the password first.
- How strong is the encryption?
- AES-256 under PDF security revision 6, the strongest the PDF standard defines and the one current software expects. The practical weak point is the password itself, so make it long.
- What happens if I forget the password?
- The document is gone. AES-256 cannot be bypassed or recovered — not by you, not by us. That is the entire point of encrypting it, so keep the password somewhere safe.
- Do you keep my password?
- No. It is used to encrypt the file during your request and is never written down — not in a database, not in a log line. There is nothing to breach because nothing is kept.
- Can I remove the password later?
- Yes, with the unlock tool — as long as you know the password. Protect and unlock are deliberately a matching pair.