Check if a PDF is properly redacted — without uploading it
Find text hiding under black boxes, redaction marks that were never applied, and leftover metadata.
Processed on your device — nothing is uploaded. Works offline.
Drop a PDF that has already been redacted. The checker renders every page, finds the dark boxes, and looks for text still sitting underneath them — the copy-and-paste leak — plus redaction marks that were never applied, leftover search terms and identifying metadata. The file is inspected in your browser and never uploaded.
How to check if a PDF is properly redacted — without uploading it
- 1Drop the redacted PDF onto the page. Every page is rendered and inspected in your browser.
- 2Read the verdict: text found under dark boxes is listed page by page, along with unapplied redaction marks and identifying metadata.
- 3Optionally type the names or numbers that were supposed to be removed. The report says on which pages they survive, or whether they linger in the raw file bytes.
- 4If anything is recoverable, redact the original properly with Redact PDF, which destroys the text and re-runs this check on its own output.
Every step runs in this tab. The site has no upload endpoint, and the page's security policy forbids the browser from contacting any other server — see how that is enforced.
When you'd use it
Before a filing leaves the office
Court documents, discovery bundles and FOI responses where a copy-paste leak makes headlines.
Documents redacted by someone else
A supplier or opposing party sends a 'redacted' file; find out in ten seconds whether it is.
Files redacted with a drawing tool
Black rectangles from a viewer or an image editor look right on screen and hide nothing.
Good to know
- Each page is rendered and every text run is checked against the pixels where it sits: text on uniformly dark pixels is covered, not visible, and is reported with the words themselves. White text on a dark banner is visible and is left alone.
- Redact annotations are the marks Acrobat and others create before you click Apply. If they are still in the file, nothing was removed.
- The checker reads the file's own text layer. A scan has none, so boxes on a scan only hide pixels; check the metadata and any OCR layer instead.
- Nothing is modified and nothing is downloaded; this is a read-only inspection.
Don't trust us — test us
“Your files never leave your device” is a claim every PDF site makes. Here it is checkable in under a minute, three different ways:
- Watch the network.Open your browser's developer tools, switch to the Network tab, then run the tool. The only requests you will see are the site's own files — none of them carries your document — and once the app is cached there are no requests at all.
- Pull the plug. Load this page, turn off your wifi or switch on airplane mode, then use the tool. It keeps working, because there is no server involved and nowhere to upload to.
- Read the headers. The response headers for this page include a Content-Security-Policy with
connect-src 'self': the browser itself refuses to send anything to another host, whatever the code asks.
The full privacy model, including what we can't protect you from →
Guide
How to redact a PDF without uploading it
Uploading a document to redact it is backwards: the whole point is that the contents are sensitive. How to do it locally, and why a black rectangle is not a redaction.
Frequently asked questions
What does this checker actually detect?
Four things: extractable text sitting on uniformly dark pixels of the rendered page (covered, not visible), redaction annotations that were never applied, any search terms you enter that still appear in the text or in the raw bytes, and document metadata such as title, author, keywords or an XMP stream.
My file shows text under a box. What now?
The box was drawn over the text instead of removing it. Redact the original document again with a tool that rebuilds the page, such as Redact PDF here, and check the new output.
Can it check a scanned PDF?
It will render it and look for boxes, but a scan has no text layer to leak. The risk there is a hidden OCR layer or metadata, both of which the checker reports.
Does the checker keep or upload my document?
No. It runs entirely in your browser and never sends the file anywhere. Load the page, turn off your wifi and run the check to see for yourself.
Does it work offline?
Yes. After your first visit the whole app is cached by a service worker, so the page loads and every tool works with no connection at all. Load the page, switch on airplane mode, and carry on.
Is there a file size limit?
No hard limit — your device's memory is the ceiling. Files up to a few hundred MB work well on a typical laptop. Very large files may be slow or fail on low-memory devices; nothing is ever truncated silently.
Do I need to create an account?
No. No account, no email, no cookies. The free tools are simply free.
Which browsers work?
Current Chrome, Edge, Firefox and Safari, on desktop and on phones. Phones have less memory, so very large files are better handled on a laptop.