Redact by Pattern - Free Online Browser Tool

Find every match of a regular expression across a document and remove the matched text for good.

Literal keyword redaction handles the names you already know about. It does not help with a format — every account number, every reference that looks like ACC followed by digits, every string matching a shape. A pattern covers whole classes of them at once.

This redact by pattern utility runs completely inside your web browser. Your document is opened locally and processed on your own device using JavaScript and WebAssembly, so your file is never uploaded to any server. There is no signup, no watermark and no limit on how many documents you can handle.

  • 100% client-side - files never leave your device
  • Instant processing, no upload wait
  • Works on desktop, tablet and mobile
  • Free forever, no account required

Common next steps: Bulk Keyword Redaction, Shapes & Redaction Boxes, Sanitize Tracking IDs.

How to Use the Redact by Pattern Tool

Four steps, and the whole thing runs locally on your own device.

  1. Enter a pattern or pick a preset

    Presets cover common identifiers. A typed pattern can be any valid regular expression.

  2. Choose case sensitivity

    Matching either case catches more; matching only one case avoids false positives on ordinary words.

  3. Run the scan

    Every page is read and matches are counted and listed. Nothing is removed.

  4. Review the preview, then redact

    You get a marked-up preview and a match list. Run bulk redaction with those exact values to remove them.

Frequently Asked Questions

Why does it not just redact directly?

Because a pattern that is slightly wrong removes far too much, and that damage is not reversible. The preview makes you look before you act, which is the only sane way to run a regex over a document.

What if it finds nothing?

The document is probably a scan with no text layer, which needs OCR first, or the pattern is too strict. Both are reported rather than producing an empty result.

Is a preview PDF real redaction?

No, and the bundle says so in capitals. It is for checking where the pattern landed. The actual removal is done by the keyword redaction tool using the values this one found.

How accurate is the match position?

The report is exact — it lists the matched text and the page. The boxes drawn on the preview PDF are indicative, positioned in reading order rather than at exact glyph coordinates.

What makes a pattern dangerous?

Breadth. Something like three dots will match almost everything on a page. Start with the narrowest pattern you can, read the match list, then widen if it is too conservative.