Add your file from your device.
01PDF toolTool result
Protect PDF
Add a password to a document before sharing it.
100% FreeBrowser-basedNo watermark
- 1UploadAdd your file from your device.
- 2Choose optionsPick the output settings you need.
- 3ProcessRun the tool in your browser.
Private by designProcessed on your device where possible.
Works on any deviceDesktop, tablet and mobile browsers.
No installationOpen the page and start working.
Always free coreUse the free plan for everyday tasks.
How to use Protect PDF
Pick the output settings you need.
02Run the tool in your browser.
03Save the finished result.
04Your files stay private
Your work is processed locally in your browser where possible and is never added to a Vootkit upload library.
Learn more about privacyBefore setting a password it is worth knowing which of the two kinds you are setting, because only one of them actually protects anything.
What Protect PDF does
Sets a password on a PDF so it cannot be opened without it.
One caveat stated plainly: encryption depends on the PDF engine build, and if this browser build does not include it you will get an explicit error rather than a file that looks protected but is not. Silently producing an unprotected document would be far worse.
Passwords and what they do
| Minimum password length | 4 characters |
|---|---|
| Open password | Genuinely encrypts — the file cannot be read without it |
| Permissions lock | Only discourages printing and copying; trivially removed |
| If encryption is unavailable | You get a clear error, never a false sense of security |
| Recovery | None — lose the password and the file is unreadable |
| Accepts |
Detailed steps
- Drop the PDF in.
- Enter a password of at least four characters — and make it a real one, since anything worth encrypting is worth more than four characters.
- Save the password somewhere you will still have it later.
- Protect and download.
Worth knowing
Never send the password down the same channel as the file. A protected PDF and its password in the same email thread is exactly as secure as an unprotected PDF, and it is the most common way this goes wrong.
Frequently Asked Questions
I lost the password. Can it be recovered?
No, and that is the point of encryption. There is no reset and no back door. Anything claiming otherwise is either guessing common passwords or lying about what it does.
It says encryption is not supported. What now?
The PDF engine build in your browser does not include it. Use your operating system’s “export as protected PDF”, or a desktop tool. The error appears deliberately rather than handing you a file you would wrongly trust.
What is the difference between this and a permissions lock?
An open password encrypts the contents and is genuinely secure. A permissions lock leaves the file readable and only flags that printing and copying are discouraged — which readers may ignore, and which Remove PDF Password strips in seconds.
Is a four-character password enough?
It is the minimum this tool accepts, not a recommendation. Four characters is guessable almost instantly. If the document is worth encrypting, use a long passphrase.
Is Protect PDF free?
Yes. The Vootkit free plan includes 5 tool runs a day. Upgrade to Vootkit Pro for unlimited daily use, an ad-free workspace and saved workflows.
Are my files uploaded?
No. Protect PDF runs entirely in your browser — your file is processed on your own device and never sent to a server. There is nothing for us to store or delete.
Do I need to install anything?
No. Protect PDF works in any modern browser on desktop, tablet or phone. Open the page and start.
How often can I use it? Is there a daily limit?
On the free plan you get 5 tool runs a day. When you reach the limit you'll see a prompt to upgrade, and it resets the next day. Vootkit Pro removes the cap entirely for unlimited daily use.
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This tool processes everything locally in your browser. You can disconnect from the internet after the page loads and it will still work.