How do I do a "true" redaction without the paid tier?

After redacting in PDFCatalyst, re-export the file via your OS's print-to-PDF. macOS Preview: File → Export as PDF. Windows: print to "Microsoft Print to PDF". Linux: most distros ship a "Print to file (PDF)" option. The flatten step rasterises each page, dropping the underlying text data; what remains is just the visual content (including the black redaction boxes). The result is roughly equivalent to a properly-redacted scan.

Can I redact a scanned PDF?

Yes — and for scans, the redaction IS true redaction by default. Scanned PDFs have no underlying text layer (it's just an image of the page), so a black rectangle drawn over the image hides the content with no recoverable text underneath. For scanned PDFs that have been OCR'ed (so they have a hidden text layer), you'll want the v1.1 OCR-aware redaction or the OS-level flatten step described above.

Can I undo a redaction?

Within the editor session: yes, Cmd/Ctrl+Z reverses the most recent redaction. The original PDF you dropped is held unchanged in browser memory until you click Download. Once you've downloaded the redacted version, the redaction is permanent in that file (the original is still in your browser).

Does the redaction print correctly?

Yes — the black redaction rectangles are part of the PDF's drawing instructions, so any PDF viewer (Acrobat, Preview, Foxit, browser-built-in) renders them on print. The print output looks identical to the on-screen view: black boxes covering the redacted content.

Do my files leave my browser?

No — at all, today. All editing runs client-side via pdf.js and pdf-lib. The v1.1 paid tier will add opt-in cloud OCR / unlock; even then files are deleted within 60 seconds.

Yes. Everything in the editor today (annotations, AcroForm fill, watermark, page numbers, split, merge, export) is free forever. Paid tier ($1.99/document) covers cloud OCR + AI autofill on scanned PDFs in v1.1.

How do I keep my work between sessions?

Edits autosave to your browser's IndexedDB every 500 ms. The editor URL becomes /app?s=… — copy or bookmark to return. Sessions live entirely on your device.

Can I use this for sensitive documents — tax, medical, legal?

Yes — that's the point of client-side execution. Your tax return, medical record, or legal contract literally never touches our infrastructure. Verify in DevTools' Network tab.

Does Vietnamese text export correctly?

Yes. The export pipeline auto-fetches Roboto-Vietnamese (with full diacritic coverage) when any annotation contains non-ASCII text.

Redact PDF

Redact sensitive content in a PDF. Online, free.

Drag a black rectangle over any account number, signature, or name you don't want to share, then download. The redaction is rendered as an opaque shape in the page's drawing instructions — visible in any PDF viewer, persistent through edits.

Drop your PDF here

or click to browse · 10 MB max free · stays in your browser

Open the free editor How it works

Files never leave your browserNo signup requiredDrag-to-redact · opaque black boxes · client-side

FREE TIER

$0 forever

Black-box redaction · drag any rectangle · client-side

Open editor

TRUE REDACTION · v1.1

$1.99 / document

OCR-aware redaction · removes text data, not just visuals · ships with v1.1

See pricing

The full guide

Everything you need to know about redacting PDFs online.

Redaction vs. deletion vs. erasure

Three operations look similar but mean different things. Redaction draws an opaque black box over content — the text is still in the file, but visually obscured (this is what most "redact PDF" tools mean). Deletion removes the page entirely. Erasure draws a white box over content, which looks like the content is gone but is also still there underneath. PDFCatalyst supports all three; pick redaction when you want a clear visual signal that something WAS removed.

A note on "true" redaction (and why it needs OCR)

PDFCatalyst's free redaction draws an opaque black rectangle over the content. The original text data is still in the underlying PDF — anyone who opens the file in Acrobat and selects text under the redaction can copy it out. For "true" redaction (where the text data is also removed from the underlying stream), you need OCR-aware redaction that knows where the text glyphs are. That's on the v1.1 paid tier ($1.99/document) because it requires server-side OCR. For visual redaction in social or business contexts, the free version is enough; for legal-grade redaction (court submissions, FOIA responses), upgrade.

Common redaction targets

Five categories cover most redactions: account numbers and routing numbers (for financial documents you're sharing for non-payment purposes), signatures (when forwarding a signed contract for review without sharing the signer's actual signature image), national IDs / SSNs / CCCD numbers, full home addresses (when sharing tenancy or proof-of-address documents), and other people's names (when sharing a multi-party document for review by one party). The free black-box redaction works for all five.

Privacy: redaction runs entirely in your browser

Server-side redaction tools have to upload the WHOLE PDF — including the unredacted source — to draw a few black boxes on it. The full unredacted document passes through their TLS termination, RAM, and possibly a queue before the redaction is applied. PDFCatalyst's redaction runs in your browser tab via pdf-lib, with the source bytes never leaving your device. The unredacted version of your document is never accessible to anyone but you.

Redacting then sharing safely

Two-step recommendation for sharing redacted documents: (1) redact in PDFCatalyst, (2) re-export and re-flatten via a print-to-PDF step in your OS (macOS Preview's "Export as PDF", Windows "Microsoft Print to PDF") to convert the redaction layer into a flat raster page. The flatten step ensures the underlying text data is gone, not just visually obscured. For business and personal use, the in-browser redaction alone is fine; for legal/medical use, do the flatten step too.

How it works

Redact PDF in 4 steps.

01
Open the PDF
Drop your PDF onto the editor at /app or click to browse from your device.
02
Pick the Redact tool
Click the redact icon in the left toolbar. The cursor becomes a crosshair.
03
Drag over content
Drag a rectangle over the text or area you want to black out. Multiple redactions: keep dragging.
04
Download
Click Download to save the redacted PDF. The black boxes show in any viewer; flatten via OS print-to-PDF for legal use.

Frequently asked questions

Questions about this tool.

In the free tier: no — the black box covers the text visually, but the underlying text data is still in the PDF stream. Someone who opens the file in Acrobat and uses the text-selection tool over the redacted area can copy the original text out. For "true" redaction (text data fully removed), the v1.1 paid tier ($1.99/document) handles it via OCR-aware redaction. For social and business sharing, the free version is enough; for court submissions or HIPAA-grade redaction, upgrade or flatten via OS print-to-PDF.

Redact your PDF in your browser. Free.

Drag a rectangle over sensitive content, download. The unredacted version never leaves your device.

Open the free editor