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Password Protect PDF

Add a password to your PDF so only people you trust can open it. Files are locked with 256-bit AES encryption right in your browser, and neither the document nor the password is uploaded. Free, with batch support.

Import and password

Add the PDFs you want to secure, then choose the password that should be required to open the locked files.

Drag & drop PDF files here or

PDF only. Limits: up to 200 files and about 1 GB total.

Use a unique password with at least 8 characters. Longer is better.

Most users can keep this enabled. Use a separate owner password only when your workflow needs it.

PDF files and downloads

Locked PDF downloads activate after protection is applied. Download one file or collect the batch as a ZIP.

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No files yet - add PDFs on the left.

Password protect a PDF with AES-256 encryption

Locking a PDF means anyone who opens it has to type the password first. This tool uses qpdf, a well-known open-source PDF library, to encrypt the file with 256-bit AES, the strongest encryption the PDF format supports. Adobe Acrobat, Chrome, Edge, Preview on Mac and phone PDF apps all ask for the password before showing a single page.

Use it before you email a salary slip, bank statement, medical report, contract or tax return, or before you store sensitive documents in a shared folder.

How to add a password to a PDF

  1. Add the PDF files. Several files can share one password.
  2. Type a password. The strength meter turns green for long passwords with mixed characters.
  3. Press Lock PDFs. Each file is encrypted in your browser.
  4. Download the locked copies, named file_locked.pdf, or all of them as a ZIP.

Open password and owner password

Open (user) passwordNeeded to open and read the file. This is the one to share with the person you send it to.
Owner passwordUsed to change the document's security settings. Leave it the same as the open password unless you need them to differ.

There's no way to recover a forgotten password, and that includes us. Keep it somewhere safe, and send it by a different channel than the PDF itself, for example by text message instead of in the same email.

Your files and passwords never leave your device

Encryption runs in your browser through WebAssembly. Neither the PDF nor the password is sent to a server, which is exactly what you want from a tool that protects private documents. It's free, with no sign-up or watermark. To remove a password later, use Unlock PDF.

PDFUnlock PDFRemove a password you know.Open toolPDFMerge PDFCombine files before locking.Open toolCompressCompress PDFShrink the file before locking.Open toolImageAdd WatermarkMark images before sharing.Open tool
Lock PDF guideLock PDF guideChoose and share passwords safely.Read guideBrowser file privacyBrowser file privacyWhat stays on your device and why.Read guideSafe file workflowSafe file workflowHandle sensitive documents carefully.Read guide

PDF password questions

How do I password protect a PDF for free?

Add the PDF, type a password, press Lock PDFs and download the locked copy. It's free, with no sign-up.

How strong is the encryption?

Files are encrypted with 256-bit AES through qpdf. That is the strongest standard encryption available in the PDF format.

Can I lock several PDFs at once?

Yes. Add multiple files and they all get the same password. Download them one by one or as a ZIP.

What if I forget the password?

It can't be recovered. Keep a copy of the original unlocked file and store the password safely.

Will the locked PDF open on a phone?

Yes. Any standard PDF reader on Android, iPhone, Windows or Mac will ask for the password and then open it.

Is my password sent anywhere?

No. The PDF and the password stay in your browser on your device.