Skip to content
Klarmask

Redact a PDF or a Word document

The numbers, addresses and names you decide to redact are removed from the file, not just hidden. Nothing is sent.

How it works

  1. Drop the document

    A PDF or a Word document (.docx). It is read by your browser, in this tab. Suggestions appear within a few seconds.

  2. Decide on each suggestion

    On the right, suggestions grouped by type; on the page, highlighted. Redact, keep, redact a name everywhere, draw an area. J and K to move from one to the next, M to redact, L to keep, Ctrl+Z to undo.

  3. Produce the file

    The button becomes active when everything is decided. The tool rebuilds the document, reads it back, then offers it to you: your browser saves it.

What is detected, and how

DataCheck
Names of people and companiesA model that runs in your browser, downloaded once from this site and verified; the forms of the same person are grouped
IBANCountry length and modulo 97 check digits
RIB (French bank details)RIB key
NIR (French social security number)Two-digit key, including Corsica (2A, 2B)
SIREN, SIRETLuhn check, with the exception for La Poste establishments
EU VAT numberKey calculated from the SIREN
Bank cardLuhn check and known prefix
Phone number, email, IP addressFormat
Postal addressNumber, street type, postcode and town
Date of birthOnly when the text says “born on”, “date of birth”
Number plate, passport, tax numberFormat, with the context when it is ambiguous

A correct format with a wrong check digit is suggested “to review”: it is often a typo in the document, and the data is still personal. Bulk decisions never touch what is to review.

Word documents

A Word document is an archive of files: the text, but also tracked changes, comments, properties (author, company), fields and links. A name hidden in one of these parts survives a find and replace.

Klarmask does not clean the document: it writes a new one, with only the parts it understands. Tracked changes are accepted (deleted text disappears along with its author), comments and properties are removed, and each redacted value is replaced wherever it appears: in the text, even when split across several formatting runs, in headers, footers, notes, text boxes, fields, image alt text and link addresses.

The file produced is read back as for a PDF: every paragraph, every attribute and every image is walked through, and the structure of the package is checked before it is offered to you.

What it does not do

  • Find every name for certain. The model suggests them and can miss some: “Redact everywhere” redacts a missed name throughout the document, including when it is split at the end of a line.
  • Handle every language equally. Detection is tuned for documents written in French: French identifiers (NIR, SIREN, SIRET, tax number), phone numbers and addresses in French format, and a name model trained on French. In other languages, fewer names may be suggested.
  • Read a scan: a PDF with no text suggests nothing, draw the areas by hand.
  • Open a password-protected PDF: remove the protection first.
  • Keep the links, forms and accessibility tags of a PDF's pages: they are rendered as images.
  • Read the content of images in a Word document: a signature or a stamp in an image would remain visible. Tick “Remove the images” in that case.
  • Keep the charts and embedded objects of a Word document: they are removed. Open a .doc file (Word 97-2003): save it as .docx first.