Protect a PDF with a password - encryption happens locally, the password never leaves your device. No upload.
Running locally on your device ...
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Contracts, payslips, ID scans: some PDFs should only open with a password. This tool encrypts your document and sets a password that is required to open it.
Choose a password the PDF will require to open from now on. The document is secured with standard PDF encryption; without the password it can no longer be opened - so keep it safe.
Important to understand: encryption transforms the content so it is unreadable without the correct password - the protection lives in the file itself, not in a padlock icon on top. So choose a strong, unique password and share it over a separate channel, not in the same email as the PDF. And remember it well: there is no back door and no reset, a forgotten password locks you out for good.
You can additionally set a separate owner password with permission restrictions (block printing, copying, editing, commenting) - with no password to open the file at all. This feature is part of the PDF standard and exists in Smallpdf, Adobe Acrobat and iLovePDF just the same - and the same technical truth applies everywhere: permission restrictions are far weaker than a real open password. A PDF application that follows the standard honors the restriction, but it can be removed without the owner password (our own "Unlock PDF" tool does exactly that). Use it as a convenience and intent signal, not as protection against someone who really means to bypass it.
| Input formats | |
|---|---|
| Auto-conversion | PNG, JPG, WebP, GIF, BMP, TIFF, ICO, SVG, HEIC, ZIP, DOCX, 7Z, DDS, HDR, PCX, WBMP |
| Output format | |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: Sets a password to open (standard PDF encryption, real protection) and/or a separate owner password with permission restrictions (printing/copying/editing/commenting). Permission restrictions without an open password are only a statement of intent: they can be removed with suitable software without knowing the owner password (see our "Unlock PDF" tool). A forgotten open password cannot be recovered by anyone.
No, encryption and password stay entirely local in the browser.
Then the PDF can no longer be opened - nobody can recover the password. Keep it safe.
Yes: set an owner password and pick the restrictions you want (printing/copying/editing/commenting) - this works entirely without an open password too. It is technically weak, though: a standards-compliant application honors it, but it can still be removed without the owner password, for example with our own "Unlock PDF" tool. For real protection, also set an open password.
Yes, only encryption is added; pages and content stay the same.
The tool uses standard PDF encryption; the strength follows your file's PDF version: common PDF 1.6/1.7 documents get AES-128, newer PDF 1.7ext3 files AES-256, and very old versions the earlier RC4 handler. No encryption helps against a weak password - pick a long, unique one.
Use the "Unlock PDF" tool together with the password.
Nothing serious: the PDF still opens and reads normally, you just can no longer deliberately lift the restriction with the password - "Unlock PDF" removes it anyway even without one.
Yes, completely free - no account, no watermark, no cap on documents. Encryption happens on your device, not on a server.
An open password is meant to stay a secret - with an online service you have to send exactly that secret, together with the file, to someone else's server. Here the encryption is computed in the browser: the password and the PDF never leave your device.
Unlock PDF · Watermark PDF · Merge PDF · Redact PDF · Encrypt file · Edit PDF