Nothing is uploaded = your ID number is never stored anywhere

Black out personal data in documents and IDs

Finds ID, account and card numbers and covers them — plus front/back merging and a "for submission" watermark. Your file never leaves your computer.

Drop an ID photo or a PDF here, or click to choose

JPG · PNG · PDF — drop both sides at once — processed entirely on your machine

Choose file

Why not just use an image editor

So it is not rejected

Platforms reject documents that are not properly masked. What you should cover depends on who is asking — the rules differ by country and by institution. Nothing is covered until you mark it, and you can add or remove any area yourself.

It is really gone

A black rectangle drawn over PDF text still leaves the text underneath — copy it out and the original is right there. Redacted pages are rendered to pixels so the text is actually removed.

The number never leaves

Both the finding and the covering happen inside this browser tab. Neither the file nor the text read out of it is sent anywhere.

Black out ID and card numbers so they cannot be recovered

Landlords, employers and online platforms often ask for a copy of an ID or a statement, yet rarely need every digit on it. This tool finds personal numbers in a PDF and covers them, lets you drag over anything else by hand, and saves a copy in which the covered parts are truly gone. Finding, covering and saving all happen in your browser; neither the file nor the numbers read from it are sent anywhere.

A closer look

When a PDF has a real text layer, the tool reads each page and looks for Korean resident registration, account and mobile numbers, card numbers, passport numbers and email addresses. Resident numbers are checked against their check digit and card numbers against the Luhn rule, so a random string of the right length is not blacked out by mistake. Other countries’ national ID numbers are not detected yet, so drag over those yourself. Detected items are covered partially, following common practice: a card number keeps its first six and last four digits visible, and an email address keeps its first two characters. Every hit appears in a list with its type and masked form so you can compare before saving.

A black rectangle placed over PDF text only hides it from view; copy the page and the original comes straight back. So every page with at least one box is re-rendered at 300 dpi and saved as a picture. The original characters are no longer in the file and cannot be restored, and in exchange that page can no longer be searched or selected and usually gets larger. Pages you did not touch are copied over unchanged. Photos (JPG, PNG) have no text layer, so nothing is detected automatically; you cover them by dragging, and the result is saved as a JPG.

How to use it

Open an ID photo or a PDF. If you drop front and back photos together, Combine front and back into one image appears and stacks them vertically. Decide on it first, because switching it clears boxes you have already drawn.
For a PDF, detected items are blacked out right away and a message such as “Found 3” appears with the list. Use Previous page and Next page to review a multi-page file.
Drag over anything that was missed, and click an existing box to remove it. Undo removes the last box on the current page, and Clear all removes every box.
If the copy is meant for one recipient, tick Add a “for submission” watermark and type who it is for. Then press Save; the file downloads with “_redacted” in its name.

When it helps

Rental applicationsSend a landlord an ID copy with the digits they do not need covered and a watermark naming the property.

Income paperworkCover the ID number on a pay or tax statement so only the amounts the recipient asked for remain readable.

Two-sided cards in one uploadMerge the front and back photos of a driver’s license into one image for a form that takes a single file.

Sharing an internal listBlack out phone numbers and emails on a report’s contact page while the other pages stay searchable.

Common snags

It says “Nothing was found automatically”.The file is a photo or a scanned PDF with no text layer, or the number is stored in the PDF as several separate fragments. Drag over the area yourself; manual boxes are baked into pixels exactly like detected ones.

The watermark reads “For submission to ___”.With the watermark switched on and the text box left empty, the placeholder text is stamped as is. Type the recipient’s name and save again.

My whole PDF became unsearchable.A watermark has to be painted onto every page, so every page is rendered to pixels. Leave the watermark off if untouched pages need to stay searchable; then only pages with boxes become pictures.

A long PDF makes the tab slow.Every page is drawn at 300 dpi and kept in memory while you work. Pull out only the pages that need covering with Split PDF, redact that smaller file, and the tool stays responsive.

Tip Treat automatic detection as a starting point. Before saving, compare the number of hits in the list with the black boxes on screen, and look for numbers written by hand or inside a stamp, since those are not stored as text.

FAQ

What does it find automatically?

Korean resident registration numbers (checksum-verified), Korean account and phone numbers, card numbers (Luhn-checked), passport numbers and email addresses. Other countries’ ID numbers are not detected yet — drag over them yourself. We would rather mark nothing than black out something that should have stayed visible.

What if it misses something?

Photos (JPG, PNG) contain no text layer, so nothing can be detected automatically — drag over the parts you want covered. Scanned PDFs have the same limitation.

Can the redaction be undone?

No. Redacted pages are re-rendered as pixels, so the original text is not in the saved file. The trade-off is that those pages are no longer selectable or searchable.

Is my file uploaded?

No. Opening, detecting, covering and saving all happen in the browser. It works with your connection switched off.