hddn Hide what matters.
How it works

How to redact and edit a PDF in your browser

See how hddn works in your browser: open a PDF, black out or edit what you choose, review it, and export a clean copy. Nothing is uploaded.

Step 1 - Open your PDF

Drop your file into the page.

Your browser opens the PDF directly on your device.

Step 2 - We mark possible sensitive data

The tool highlights things that may need to be hidden, such as:

  • names
  • emails
  • phone numbers
  • IDs or other personal details

These are only suggestions.

Step 3 - You review everything

You decide what should be removed.

You can:

  • keep or remove the suggested markings
  • black out any text or area yourself if something was missed
  • edit the words directly, when the PDF is digital

You stay in control of the document.

Step 4 - Export a clean file

When you're ready, export the PDF.

The selected data is permanently removed from the file.

You can then share the redacted version with more confidence.

How this works without uploading your file

When you open hddn, the site loads the redaction workspace into your browser. After that, your browser can open and edit your PDF locally.

This means:

  • your file stays on your device
  • it is not uploaded or sent anywhere

You can load offline tools, disconnect, refresh /redact, and test this workflow yourself.

Important

The tool helps you find sensitive data, but it may not catch everything.

Always review your document before exporting and sharing it.