Processed on-device · pdf.js + pdf-lib

Redact PDF Online — flatten redacted pages to remove their original page text and graphics from the output

Draw boxes over sensitive text or images in your PDF. Redacted pages are rebuilt as images during export, while untouched pages retain their original content. Review the result before sharing.

How this works: Redacted pages are rebuilt as images with the redaction boxes included in the rendered pixels. This is different from placing a black rectangle over the original PDF content. Review the output carefully before sharing sensitive documents.

See the four steps
Content removed via page flattening Move, resize, delete boxes safely Apply to one, all, or specific pages Your PDF stays in your browser
Built & maintained by Bhavin J. Sheth | Updated

The redaction console

Upload a PDF, draw boxes over what needs to disappear, then apply.

Redacted pages are flattened, not just covered

When you apply redactions, any page with a box on it is converted into an image with the box baked into the picture. The original text and graphics on that page are not included in the output file — only pages with no redactions keep their original searchable text.

Drop your PDF here

or browse files

Why redaction has one job

A redaction has to destroy the content, not just hide it

A black box that merely sits on top of a PDF's existing text solves nothing — the words are still there underneath, fully intact, waiting to be selected. Real redaction removes them.

What a cosmetic black box does

A visual black box is not the same as true PDF redaction. If the original page content remains in the document underneath the box, that content may still be selectable, searchable, or extractable.

The text underneath is completely untouched. Select all the text on that page, copy it, and the "redacted" content pastes out in plain, readable text. This is a well-documented, real-world way sensitive information has leaked from documents that looked safely redacted.

What this tool does instead

Any page containing at least one redaction box is rendered to a flat image, with the box drawn directly into the pixels, before that page is placed into the new PDF.

The original text and vector content for that redacted page are not copied into the rebuilt page. The resulting page contains the rendered image with the redaction boxes included. Other pages remain unchanged, so review the complete document and its metadata before sharing.

Build notes

The write-up on how this was built

Because getting redaction genuinely right matters more than almost anything else on this site, I wrote up the implementation in detail — how the flatten step works, and why drawing a shape on top of a PDF page is not the same thing as redacting it.

Published on freeCodeCamp

How to Build a PDF Redaction Tool That Actually Removes Content

Covers the difference between overlay-based and flatten-based redaction, rendering pages to canvas with pdf.js, and rebuilding a PDF with pdf-lib so covered content cannot be recovered.

Read the write-up on freeCodeCamp

Written by Bhavin Sheth · Founder, AllInOneTools

Draw, adjust, then apply — in that order

Everything is fully editable until you click Apply & Finalize — after that, it's permanent.

1

Upload your PDF

Drag it onto the upload area, or click Select PDF. The first page loads into the redaction console right away.

Page through the document with the arrows to find what needs redacting.
2

Draw and adjust boxes

Click and drag on the page to draw a box, then fine-tune it:

Move: drag anywhere inside a box.
Resize: drag the handle in the corner.
Delete: click the × on the box, or use the list.
3

Choose which pages

By default, boxes only apply to the page you drew them on. Use Apply to Pages if you need this page's boxes copied elsewhere.

Check every page before finalizing — this step can't be undone afterward.
4

Apply and download

Click Apply & Finalize. Redacted pages are flattened, then the file is ready to download.

Content genuinely removed Nothing uploaded

Documents where a cosmetic black box isn't good enough

Cases where the difference between "hidden" and "removed" actually matters.

Common situations for redacting a PDF, by user type
Use caseWhat needs removingTypical user
Legal document sharingClient names, case details, or privileged information before sharing a filing externally.Lawyers & paralegals
Financial recordsAccount numbers, government-issued identification numbers, or salary figures before sharing a document for review.Accountants & finance teams
HR & employee recordsPersonal details in internal documents before wider internal distribution.HR departments
Medical documentationPatient names or identifying details before using a document for research or teaching.Healthcare administrators
Public records requestsPersonal information exempted from disclosure before releasing a government document.Public records officers
Contract negotiationCommercially sensitive terms before sharing a draft with a third party.Business & procurement teams
Exactly what happens on Apply

How flattening actually removes the underlying content

No black-box magic — here's the literal sequence of steps that happens to each page.

1

Check each page for redaction boxes

Pages with no boxes drawn on them are set aside — they'll be copied into the final PDF completely unchanged, keeping their original text, quality, and searchability.

2

Render redacted pages to a canvas

For every page that does have a box, the page is rendered fresh at high resolution onto an image canvas — the same rendering pipeline used for the on-screen preview, just at export quality.

3

Draw the black boxes into the pixels

Each redaction box is filled in solid black directly on that canvas, at the exact position and size you set — not as a separate layer, but as part of the image itself.

4

Replace the page with that image

The canvas becomes a single embedded image on a brand-new page in the output PDF. The original page's text, fonts, and vector graphics are not copied into that rebuilt page. Pages without redactions retain their original content, so review the complete PDF before sharing.

5

Assemble the final file

Untouched pages and flattened pages are combined into one PDF in the original page order, then made available to download.

When something doesn't look right

What's actually happening, and the fastest way through it.

Symptom
Why it happens
Fix

Text after the redacted page is no longer selectable

Any page with a redaction box is flattened into an image, which by design has no separate text layer.

Expected — this is exactly what guarantees the covered content can't be extracted. Pages without redactions stay fully searchable.

Output file is noticeably larger

Flattened pages become images, which are typically larger than the original vector or text content.

Run the result through Compress PDF afterward if size matters.

A box drawn on one page appeared on others too

Apply to Pages was set to "Copy to all" or "Copy to specific" instead of "Current page only."

Switch back to "Current page only" if you only meant to redact that one page.

Metadata still shows old information

Flattening removes content from the page itself, but doesn't touch the document's Title, Author, or custom metadata fields.

Check and clear metadata separately with a PDF metadata tool if that matters for your situation.

A password-protected PDF won't load

Encrypted files can't be read by the in-browser rendering engine.

Remove the password with a PDF unlock tool first, then upload the unlocked copy.

Text no longer selectable

Why: Redacted pages become images.

Fix: Expected — that's what removes the content.

File size larger

Why: Flattened pages are images.

Fix: Compress afterward.

Box appeared on other pages

Why: Apply to Pages was set to All/Specific.

Fix: Switch to Current page only.

Metadata still shows old info

Why: Flattening doesn't touch metadata.

Fix: Clear it with a metadata tool.

Password-protected PDF won't load

Why: Encrypted files can't decode in-browser.

Fix: Unlock it first, then upload.

Redacting without leaving a gap

A working order that catches the mistakes that matter most.

Cover generously, not exactly

Draw boxes slightly larger than the text itself — a tight box that clips a letter's edge can leave a readable fragment.

Review every page before finalizing

Page through the whole document once more — it's much easier to add a missed box now than after downloading.

Check the document's metadata separately

Flattening secures page content, but title, author, and custom properties live elsewhere — clear them if they contain anything sensitive.

Verify the result yourself

Open the downloaded file and try selecting text where a box was — there should be nothing there to select.

Keep the original file separately

Redaction is one-way by design — keep your unredacted source somewhere safe in case you need a different version later.

Use "current page only" unless you mean otherwise

It's the safest default — only switch to copying boxes across pages when you're certain that's what you want.

PDF redaction FAQs

Start with the first question if you're weighing whether this tool is secure enough for your situation.

Is the redaction actually permanent, or just a black box drawn on top?

Redacted pages are rebuilt as images with the redaction boxes included in the rendered pixels. This removes the original page text and vector content from those redacted pages. Review the final PDF carefully and check its metadata before sharing.

Will pages without any redaction also become images?

No. Only pages that have at least one redaction box are flattened. Pages with no redactions keep their original text, formatting, and searchability untouched.

Could sensitive information still be hiding in the file's metadata?

This tool redacts content drawn on PDF pages. It does not remove document metadata such as the title, author, subject, keywords, or custom properties. Review the output PDF's metadata separately and remove any sensitive information before sharing.

Is it safe to upload my documents here?

Your PDF is processed locally in your browser. This tool does not upload your selected document to an AllInOneTools processing server.

Can I undo a redaction before finalizing?

Yes. You can move, resize, or delete any box you've drawn at any point before clicking Apply & Finalize. Once you finalize and download the file, the change is permanent and cannot be undone from within this tool.