Does this tool upload my PDF to a server?

No. Everything runs in your browser using PDF.js and pdf-lib. Your file is never sent to any server — it stays on your device the entire time. This is especially important for sensitive documents like legal contracts, medical records, or financial statements.

Is the redaction permanent and tamper-proof?

The tool draws solid black rectangles directly onto the PDF page content using pdf-lib. The hidden content is not embedded elsewhere in the file. However, for legally sensitive redactions (court filings, FOIA responses), we recommend also verifying the output in a PDF reader and consulting your legal team — no browser tool replaces a professional review.

What file size limit is there?

There is no imposed limit. The practical ceiling is your device's available memory. Most modern devices handle PDFs up to several hundred megabytes without issues. Very large PDFs may take longer to render the page preview.

Can I redact password-protected PDFs?

No. Remove the password from your PDF first using your PDF reader (Adobe Acrobat, Preview on Mac, or a PDF password remover), then load it here for redaction.

What happens to the text under the black boxes?

The black rectangles are drawn as opaque content on top of the existing page content. The original text or image beneath is not visible in any standard PDF viewer. For maximum security on highly sensitive documents, also consider using the Compress PDF tool afterward to strip metadata.

Does it work on mobile?

Yes. The canvas-based drawing works with touch on iPhone Safari and Android Chrome. Drag your finger to mark redaction areas on each page.

PDF 墨消しツール

ブラウザ上でPDFの機密テキスト・画像に黒塗りを描画。100%ローカル処理でアップロード不要。

100% client-side · no upload · pdf-lib

Drop a PDF here or browse

How to redact a PDF

Drop your PDF into the upload area above.
Click and drag on any page to draw a redaction box over sensitive content — names, addresses, account numbers, signatures.
Navigate between pages using Prev / Next and mark additional areas on each page.
Click Redact & Download to apply solid black boxes and save the result.

Common redaction use cases

Related PDF tools

よくある質問

Does this tool upload my PDF to a server?: No. Everything runs in your browser using PDF.js and pdf-lib. Your file is never sent to any server — it stays on your device the entire time. This is especially important for sensitive documents like legal contracts, medical records, or financial statements.
Is the redaction permanent and tamper-proof?: The tool draws solid black rectangles directly onto the PDF page content using pdf-lib. The hidden content is not embedded elsewhere in the file. However, for legally sensitive redactions (court filings, FOIA responses), we recommend also verifying the output in a PDF reader and consulting your legal team — no browser tool replaces a professional review.
What file size limit is there?: There is no imposed limit. The practical ceiling is your device's available memory. Most modern devices handle PDFs up to several hundred megabytes without issues. Very large PDFs may take longer to render the page preview.
Can I redact password-protected PDFs?: No. Remove the password from your PDF first using your PDF reader (Adobe Acrobat, Preview on Mac, or a PDF password remover), then load it here for redaction.
What happens to the text under the black boxes?: The black rectangles are drawn as opaque content on top of the existing page content. The original text or image beneath is not visible in any standard PDF viewer. For maximum security on highly sensitive documents, also consider using the Compress PDF tool afterward to strip metadata.
Does it work on mobile?: Yes. The canvas-based drawing works with touch on iPhone Safari and Android Chrome. Drag your finger to mark redaction areas on each page.

Last updated: 2026-05-20 By jarvisbox

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