Password Protect PDF
Add an open password to your PDF right in your browser — your file never leaves your device. Free, no sign-up, and honest about exactly how strong the protection is.
Nothing Is Uploaded
Your PDF is encrypted entirely in your browser. The file never touches a server, so there's no copy to leak or trust.
We Never See Your Password
The password is applied on your device and never sent anywhere — structurally, we can't read it, store it, or recover it.
Honest About Strength
This adds a 128-bit RC4 open password — enough for everyday privacy, but we won't pretend it's military-grade encryption.
Free, No Sign-Up
No account, no watermark, no file-size limits — just add a password and download the protected PDF.
TL;DR: Add an open password to your PDF right in your browser — the file is never uploaded and we never see your password. It uses 128-bit RC4, which stops casual access but isn't military-grade, and the real strength depends on your password. If you forget it, the file can't be recovered. Free, no signup, no limits.
Why Password Protect a PDF?
Payslips, contracts, bank statements, ID and passport scans, tax forms, HR documents — anything sensitive deserves an open password before you email it or drop it in shared storage. A password means that even if the file ends up in the wrong inbox or folder, the contents stay closed to anyone who doesn't have the key.
Here's the catch most tools ignore: to "protect" a confidential file, they ask you to upload it to their server first. That's the privacy paradox — you expose the document to a third party in the very act of securing it. This tool removes the paradox: your PDF is encrypted in your browser and never leaves your device, so there's no upload, no server copy, and no password for anyone else to see.
How Strong Is the Protection? (An Honest Answer)
This tool adds a standard PDF open password using 128-bit RC4 encryption, done entirely in your browser. It reliably stops casual access — anyone without the password simply can't open the file — but it is not military-grade encryption, and the real strength depends on how strong your password is.
RC4-128 is not AES-256. RC4 is an older algorithm that security experts consider dated. It's fine for keeping a document private from casual viewers, but don't rely on it against a determined attacker with time and computing power. We'd rather say this plainly than market it as "bank-level" — even Smallpdf only uses AES-128.
Your password is what really matters. Any encryption falls to a weak password, because it can be brute-forced. Use at least 12 characters mixing upper and lower case, numbers, and symbols — the strength meter helps you get there.
A forgotten password can't be recovered. Because everything runs on your device with no server and no backdoor, there is no way to reset or recover the password. Save it somewhere safe — the confirm field is there to stop typos.
Protect Your PDF Without Uploading It
Every mainstream protection tool — iLovePDF, Smallpdf, Adobe, PDF24, Sejda — processes your file on its servers, then reassures you with "encrypted transfer" and "deleted after an hour." For a confidential document, that's still a round trip to someone else's computer, where you have to trust the deletion and the transfer.
This tool skips the upload completely. Your PDF is encrypted in your browser tab, the password is applied on your device, and the result downloads locally. Load the page, disconnect from the internet, and protect the file anyway — and because the password never leaves your machine, we couldn't see or store it even if we wanted to.
How to Password Protect a PDF in 3 Steps
- 1
Open your PDF
Drag and drop the file onto the tool above, or click to browse. It loads locally in your browser and nothing is uploaded.
- 2
Set a password
Type your password and confirm it; the strength meter shows how strong it is. Remember it — a forgotten password can't be recovered.
- 3
Protect & download
Click Protect PDF. The encrypted file is built on your device and downloads right away; opening it next time will require the password.
What You Can Use This For
A handful of situations cover almost every reason people password-protect a PDF:
Email a contract or payslip
Add a password before sending sensitive documents so only the intended recipient can open them.
Share financial or tax files
Lock bank statements, invoices, and tax documents before sharing them over email or chat.
Protect ID and passport scans
Keep scans of IDs, passports, and certificates closed to anyone who happens upon the file.
Secure HR and legal documents
Put an open password on offers, NDAs, and legal paperwork before they leave your hands.
Lock files before cloud storage
Encrypt a sensitive PDF before uploading it to cloud drives so the stored copy stays private.
Send a client a private quote
Protect quotes or proposals with a password you share separately with the client.
Open Password vs Owner Password
An open (user) password controls whether someone can open the file at all. An owner (permissions) password controls what they can do once it's open — printing, copying, or editing.
This tool sets the open password, because that's what actually keeps a confidential document closed. Owner permissions are worth knowing about, but they're a soft restriction: ordinary PDF tools — including a "remove password" tool — can strip them out, so they stop honest users rather than determined ones. If you only do one thing, set a strong open password. A companion tool for removing a password you already know is planned, so protecting and unlocking stay a matched pair.
Browser-Based vs Upload-Based PDF Protection
Every tool that can password-protect a PDF works either on a company's server or on your own device:
| Aspect | This tool (in your browser) | Typical online protectors |
|---|---|---|
| Where your file goes | Never leaves your device | Uploaded to a server |
| Who can see your password | No one — it stays on your device | Sent to the service |
| Account or payment | Free, no account | Login or paid tiers common |
| Honest about strength | Yes — 128-bit RC4, stated plainly | Often vague or "bank-level" |
| File size limit | None beyond your device | Caps on free tiers |
| Forgotten password | Not recoverable (no backdoor) | Also not recoverable |
One honest note: this tool uses 128-bit RC4, which suits everyday privacy but isn't military-grade, and the protection is only as strong as your password. For genuinely high-stakes secrets, use dedicated encryption — but for keeping a document closed to casual access without uploading it anywhere, this is the simplest, most private option.
Complete PDF Tool Suite
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Sign PDF
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Resize PDF
Change page size to A4, Letter, or custom dimensions
Crop PDF
Trim margins, drag-select, or auto-crop white space
Flatten PDF
Make forms read-only — keep text searchable or lock to image
PDF Metadata
View, edit, or strip author, title, dates and other metadata
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Convert to grayscale or black & white to save colour ink
Extract Images from PDF
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WebP to PDF
Convert WebP images to a PDF, merge many into one file
Protect PDF
Add an open password to your PDF, entirely in your browser
Unlock PDF
Remove a known password or restrictions from a PDF, in your browser
Frequently Asked Questions
Everything people ask about password-protecting a PDF
Is my PDF uploaded to a server?
No — everything runs in your browser. Your PDF is encrypted on your own device and nothing is sent to a server. You can even disconnect from the internet after the page loads and it still works.
How secure is it? What encryption do you use?
It uses 128-bit RC4 — good for everyday privacy, not military-grade. It reliably stops casual access, but RC4 is an older algorithm, so don't rely on it against a determined attacker. The real strength comes from using a long, mixed-character password.
Can a password-protected PDF be cracked?
A weak password can be brute-forced; a strong one is far harder. No encryption saves a weak password, so use 12+ characters with mixed case, numbers, and symbols. Note that permission restrictions (printing, copying) can be removed by ordinary tools.
What's the difference between an open password and a permissions password?
An open password controls opening; a permissions password controls printing, copying, and editing. This tool sets the open password, since that's what keeps the file closed. Permission restrictions are a soft limit that other tools can strip out.
I forgot my PDF password — can I recover it?
No — there is no backdoor or reset. Because the file is encrypted on your device with no server involved, a forgotten password means the file can't be opened. Store it in a password manager and use the confirm field to avoid typos.
How do I make a strong PDF password?
Use at least 12 characters mixing upper and lower case, numbers, and symbols. Avoid dictionary words and reused passwords. The strength meter updates as you type so you can aim for the strong band before protecting the file.
Do I need to install software or create an account?
No — it's free, with no install and no account. It runs in any modern browser on any device, with no signup, no watermark, and no file-size limits.
How is this different from removing a password (unlock PDF)?
Protecting adds a password; unlocking removes one you already know. This tool adds an open password. A separate tool for removing a known password is planned, so the two stay a matched pair — and it's a reminder that permission locks can be undone.
Related PDF Tools
Securing and handling PDFs? These tools pair well with protecting a PDF:
- Compress PDF — reduce the file size before sharing or protecting it
- Merge PDF — combine documents into one before adding a password
- PDF Metadata — view or remove hidden author and metadata fields
- Flatten PDF — lock a filled form so it can't be edited
- PDF to JPG — turn PDF pages into image files
Ready to Password Protect Your PDF?
Free, private, and honest — add a password to your PDF without your file ever leaving your device.
Password Protect PDF Now