Open your PDF
Drop the file onto the page. Your browser opens it right on your device.
Local PDF redaction
Redact PDFs without letting them leave your device.
hddn runs entirely in your browser. Open a PDF and it flags names, IDs, and other sensitive details for you to confirm. Black out any text or area yourself, or edit the wording when the file is digital. Then export a clean copy. Nothing is uploaded, and it keeps working with your Wi-Fi off.
Processed locally in your browser. No uploads, no account.
Prove it yourself
Don't take our word for it. Turn off your Wi-Fi.
The privacy claim isn't a promise you have to trust. It's a property you can check on your own machine in under a minute.
Run the offline test- 01 Open the redaction tool
- 02 Click "Load offline tools"
- 03 Turn on airplane mode
- 04 Refresh the page
- 05 Open and redact a PDF, fully disconnected
How it works
Four steps. You stay in charge of every one.
We mark candidates
Names, emails, IDs, account numbers, and dates that may need to be hidden get highlighted.
You review everything
Confirm the marks, reject the ones you disagree with, or add your own by blacking out any text or area. On digital PDFs you can even edit the words. Nothing is hidden until you approve it.
Export a clean PDF
The confirmed data is permanently removed, not just covered, and saved back to your device.
Who it's for
For documents that can't afford a leak.
Before filing or discovery
Strip client names, case details, and identifiers from briefs and exhibits before they circulate.
Before sharing personnel files
Share contracts, reviews, and offer letters without exposing salaries or personal data.
Before statements go out
Remove account numbers, IBANs, and balances from statements, invoices, and reports.
Privacy, plainly
What happens to your document, and what doesn't.
- Your PDF is processed entirely in your browser. No processing server exists.
- Nothing is uploaded, stored remotely, or shared with third parties.
- Offline mode caches app tooling only, never your files or their contents.
- The exported PDF is saved directly back to your device.
Current scope
PDF
files only
25 MB
per file
30
pages max
Questions
Fair questions, straight answers.
Is my document uploaded anywhere?
No. The PDF is opened and processed by your own browser, on your own device. There is no processing server, and the file never leaves your machine. You can verify this by disconnecting from the internet and continuing to work.
How does offline mode work?
While connected, the tool downloads its own processing code into your browser cache. After that you can switch to airplane mode, refresh the page, and keep redacting. Only the app tooling is cached, never your files.
What does it detect?
Names, emails, phone numbers, URLs, addresses, dates, IBANs, card-like numbers, IDs, and any keywords you add. Detection is rule-based and assistive: it marks candidates, and you decide what gets removed. You can also black out any text or draw a box over any area yourself.
Can I edit the text in a PDF, not just hide it?
Yes, if the PDF is digital, meaning the text can be selected rather than being a scan or photo. You can fix a name, change a number, or delete a line, and the edit is saved into the file you export. Scanned pages can be redacted but not retyped.
Is the redaction permanent?
Yes. Exported redactions are true redactions: the underlying text is removed from the PDF, not just covered with a black box. If a document is malformed, a flattened fallback export is used instead.
What does it cost?
Nothing. There is no account, no trial, and no payment step.
Clean it up before it leaves your hands.
Free to use. No account, no upload, no payment step.
Redact a PDF