How do I password-protect a PDF before emailing my tax return?

Drop the PDF, type a strong password, hit Encrypt. Share the password through a different channel (e.g., SMS or call, not the same email). Anyone opening the PDF must type the password — even if the email is forwarded or intercepted.

How strong is AES-128 encryption?

AES-128 is the same encryption strength used by online banking and SSL. A brute-force attack on a random 12+ character password would take billions of years. Practical risk is password guessing (use a strong password) — not breaking the encryption itself.

Can I remove a password from a PDF I know the password for?

Yes — type the current password, hit Decrypt, download the unlocked PDF. Useful for removing protection from your own old PDFs once they no longer need to be secured (e.g., expired contracts you want to archive freely).

Can I crack a PDF if I forgot the password?

No — this tool only decrypts if you provide the correct password. Brute-forcing AES-128 is computationally infeasible. If you forgot your own password, you'll need to recreate the PDF from source.

What is the difference between user password and owner password?

User password (open-password) restricts opening — required to view the PDF at all. Owner password (permissions password) lets you open but restricts printing / copying. This tool sets user password by default — strongest protection.

Does Gmail still strip PDFs that are password-protected?

No — Gmail accepts password-protected PDFs (cannot scan them for viruses, but doesn't strip them). However, some corporate email gateways block password-protected attachments by policy. Confirm with the recipient if delivery is critical.

PDF Password - Lock or Unlock PDFs (AES-128) Free

Add an AES-128 user password to a PDF, or remove an existing password (you must know it). Server-side processing, files deleted after download.

Drop a PDF to lock or unlock

About PDF Password

Lock mode encrypts a PDF with AES-128 using a user password (anyone who opens the file must enter it). Unlock mode removes the password from a PDF you can already decrypt — this tool will not crack unknown passwords.

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Frequently Asked Questions

Switch to the Lock tab, drop a PDF, enter a password (and confirm it), and click Lock PDF. The output is an AES-128 encrypted PDF that requires the password to open in any PDF viewer. Distribute the locked file freely and share the password through a separate channel.

usage

AES-128 is the same encryption strength banks use for online banking. With a strong password (12+ characters mixing letters, numbers and symbols) the file is mathematically unbreakable in any reasonable timeframe. Weak passwords can be brute-forced — use a passphrase or a password manager-generated string.

technical

Yes — switch to the Unlock tab, drop the locked PDF, enter the password you already know, and click Unlock PDF. The output is the same PDF without encryption. This tool does NOT crack unknown passwords; it requires the correct password to decrypt.

features

The tool reports "Wrong password" and refuses to produce output. There is no brute-force, no retry penalty, no logging of attempts. If you don't know the password, contact the document originator — there is no legitimate way to bypass strong PDF encryption.

technical

Yes — the password is sent over HTTPS to perform the encryption/decryption server-side, then immediately discarded. We never log passwords or retain encrypted output. For ultra-sensitive workflows where even transient transit is unacceptable, use a desktop tool like qpdf or pikepdf locally.

privacy

Yes — AES-128 PDF encryption is supported by every major PDF viewer: Adobe Acrobat, Apple Preview, Chrome's built-in viewer, Foxit, Edge's PDF viewer, and mobile readers on iOS and Android.

features

Currently the tool uses a single user password (open-the-file password). Advanced PDF security separates the user password (open) from the owner password (allow/restrict printing, copying, editing) — that workflow needs a desktop tool. For most use cases, the user password is what people mean by "password-protect this PDF".

features

Free, no signup. Files up to 50MB. No watermark added during lock/unlock. Use it commercially for contracts, NDAs, tax returns and any other document that needs to be sent over email without snoopers reading it.

pricing

Use Cases

Send Tax Returns Securely

Email your tax return as a password-protected PDF and share the password through a separate channel (SMS, call). Even if the email is intercepted, the file stays unreadable.

finance

Confidential Contracts & NDAs

Lock contracts and NDAs before email distribution. Recipients need the password to open — preventing unauthorised forwarding from accidentally exposing terms.

legal

Salary & Payroll Documents

HR teams sending salary letters, performance review documents and payroll summaries should always password-protect. Personal identifiable financial information should never travel in clear PDF.

Patient Health Records

Sharing medical records between providers, with insurance, or with patients themselves should be encrypted. AES-128 PDF protection is widely accepted as adequate for HIPAA-compliant email.

health

Premium Content Distribution

E-book authors, course creators and paid newsletter writers protect their content with a download password. Combined with our PDF Watermark tool, it provides reasonable anti-piracy.

publishing

Unlock Inherited or Forgotten-Owner PDFs

You're organising old family or business documents and someone has the password. Use Unlock mode to remove the password so future access doesn't depend on remembering it.

productivity