Free PDF Password Online

A PDF that anyone can open is fine for a brochure, but completely wrong for a signed contract, an HR letter, a tax return, or a medical record. Our free online PDF Password tool lets you add a password to a PDF — or remove one you already know — entirely inside your browser. Nothing is uploaded. The encryption and decryption happen with the same well-tested AES routines used by desktop PDF software, but they run on your own device against the file you dragged in, then hand the resulting PDF straight back to you for download. To lock a document, drop your PDF onto the page, type the password you want recipients to enter, and click Protect. The tool re-saves the file with 128-bit AES encryption applied to both the document content and its metadata, which is the standard most readers (Adobe Acrobat, Apple Preview, Foxit, browser viewers) understand without complaint. To unlock a PDF you already own, drop the file in, supply the existing password, and click Remove — the tool decrypts the content and writes a clean copy with no password set. Two important notes about scope: this tool sets the user password (sometimes called the "open" password), which is what every reader will prompt for on open. It does not strip an unknown password — if you have forgotten the password, this tool cannot recover it, and neither can anyone else without the original. That is the entire point of encryption. It also does not change the underlying content; layout, fonts, embedded images, signatures, and form fields are preserved exactly. Common workflows that benefit from this tool include sending payslips and tax forms over email, sharing legal drafts with clients, distributing internal financial reports, and preparing board documents that should not be casually forwarded. Because everything happens locally, you can use it on highly confidential files without worrying about a third-party service caching them. The page works on desktop, tablet, and phone, supports drag-and-drop and the file picker, and has no limit on how many PDFs you can process per day.

Three real-world workflows this tool fits into. (1) **HR sending payslips by email**: payroll software exports a PDF per employee; protecting each one with the employee's ID number as the password takes a single drag-and-drop and stops the file from being readable if the email is forwarded by mistake. (2) **A lawyer circulating an NDA draft to opposing counsel**: the password keeps the document out of casual hands while still letting the recipient open it on any device, on any operating system, with any reader. (3) **An accountant sending a tax return to a client for review**: the same password the client uses for their portal account works for the PDF too, no extra credential to remember.

Why use this instead of Adobe Acrobat or paid online services? Adobe Acrobat Pro costs around $20 a month and is overkill if all you need is to lock or unlock the occasional PDF. Most "free" online PDF protection services upload your file to their server, where it sits in a queue until a worker processes it — for confidential documents that is exactly the wrong threat model. This page does everything locally with the same AES standard Acrobat uses, costs nothing, and never sees your file. If you also need to compress the PDF before sending (a common combo for payslips and contracts), the [PDF Compressor](/tools/compress-pdf) reduces file size first; if you need a visible "CONFIDENTIAL" mark in addition to the password, the [PDF Watermark](/tools/pdf-watermark) tool stamps every page in seconds.