Nothing is uploaded. When you drop or pick a PDF, the tool reads it locally with the browser’s File API and decrypts it on your own machine with a bundled JavaScript/WebAssembly engine (@pdfsmaller/pdf-decrypt); the unprotected copy is rebuilt in the tab and handed back as a local download. There is no server, upload, database, API or tracking in the processing path, which matters because the PDFs people unlock — bank statements, payslips, contracts, medical or legal documents — are private. They stay on your device, the tool works offline once cached, and closing the tab discards everything. The only optional network use anywhere on the site is consent-gated advertising, which never sees your files.

This tool decrypts a PDF using the password you provide; it does not attempt to recover, guess or brute-force a forgotten password. Modern PDFs are protected with strong ciphers such as AES-256, which is designed to be computationally infeasible to break by guessing — even powerful hardware would take an impractical length of time — so no honest browser tool can bypass an unknown password. If you enter the wrong password the tool reports “Incorrect password” and changes nothing. You only need one valid password: a PDF may have a user (open) password and an owner (permissions) password, and because the PDF specification lets either one decrypt the file, entering whichever you know is enough.

The tool handles the encryption schemes used by real-world PDFs: modern AES (128- and 256-bit) and the older RC4 stream cipher, covering files protected by Acrobat, Word, LibreOffice, scanners and bank or government systems. As soon as you select a file it checks whether the PDF is genuinely encrypted and shows a badge naming the cipher — for example “Encrypted (AES-256)” — so you know what you are dealing with before typing anything. If the PDF turns out not to be password-protected, it tells you no unlock is needed rather than making a pointless copy. Once you supply the correct password, it decrypts the entire document and writes out a fresh PDF with the encryption removed.

The output is the same document — every page, image, font and layout preserved — but with the password protection stripped, so it opens without a prompt in any viewer and can be printed, copied or edited normally. It downloads as your original file name with an -unlocked.pdf suffix. Because the whole process is client-side JavaScript and WebAssembly, it works in any modern browser on Android, iPhone, iPad, Windows, macOS or Linux without installing an app, and it keeps working offline once the page has been cached. One PDF is processed at a time and the practical ceiling is your device’s memory, so a very large file is bounded by available RAM.