What is the Nuvenar Redact PDF tool?
Nuvenar Redact PDF is a free, browser-side redaction tool. It renders each page of your PDF using PDF.js, lets you drag black rectangles over the regions you need to hide, then burns those rectangles into the PDF content stream using pdf-lib. The hidden content cannot be copied, selected, or recovered from the visible rendering. Your file never leaves your device.
When to use Redact PDF
- FOI responses: redact personal data, third-party references, and exempt material before releasing a document under the UK Freedom of Information Act.
- Legal disclosure bundles: redact privileged communications and irrelevant client data.
- HR and grievance documents: redact names of unrelated parties when sharing extracts.
- Financial records: redact account numbers and identifiers before sharing with auditors or third parties.
- Medical records: redact patient identifiers when sharing redacted case notes for teaching or audit.
How Redact PDF works
When you drop a PDF, pdfjs-dist renders each page to a canvas you can interact with. As you drag, the tool records the rectangle coordinates relative to the page size. When you click Apply, pdf-lib opens the source file and calls page.drawRectangle with a black RGB fill at each recorded coordinate. The output is serialised and downloaded. The rectangles are part of the page content stream, not annotations, which is why they cannot be removed by editing the PDF.
Real redaction vs annotation: why it matters
Many free tools and even some paid ones let you draw a black rectangle as an annotation. Annotations sit in a separate object that any PDF editor can delete, exposing the text underneath. There have been high-profile UK and US legal cases where redactions failed because they were annotation overlays. Real redaction modifies the content stream so the original text is not just covered but visually replaced. This tool and Adobe Acrobat Pro both do real redaction; most free online tools do not.
Redact PDF vs alternatives
| Tool | Browser-side | Watermark on free | Free tier limit | Paid price |
|---|---|---|---|---|
| Nuvenar Redact PDF | Yes | Small Nuvenar mark on free | 5 redactions per PDF | £9/mo unlimited |
| Adobe Acrobat Pro | No (desktop) | No watermark | Paid only | £15.17/mo + VAT |
| Smallpdf | No | No redact tool | Annotation only | €9/mo |
| iLovePDF | No | No redact tool | Annotation only | €6/mo |
| PDF24 Online | No | No watermark | Free, ad-supported | Free online |
Privacy and security
Redaction is almost always applied to the most sensitive content in a document. Browser-side processing means none of that touches a third-party server. Pair with our edit PDF metadata tool to strip title, author, and keyword metadata fields that can otherwise leak the original document name or author.
Common use cases by profession
- Solicitors: redact privileged passages from disclosure bundles before serving on the other side.
- Public sector and councils: redact personal data from FOI release bundles.
- HR teams: redact names of unrelated parties when sharing grievance file extracts.
- Journalists and researchers: redact source identifiers before publishing leaked documents.
- Accountants: redact account numbers and personal data from shared bank statement extracts.
- Clinicians: redact patient identifiers from records used in teaching or case review.
What is included free vs Tools Pro
Free: up to 5 redactions per PDF, any document, with a small Nuvenar marker on the output. Tools Pro at £9/mo: unlimited redactions per PDF, no Nuvenar marker, plus every other Nuvenar PDF tool (merge, OCR, metadata editor) and 25+ business calculators.
Frequently misunderstood things about PDF redaction
- Myth: a black highlight or annotation is redaction. Reality: annotations can be deleted by anyone with a PDF editor. Real redaction modifies the content stream.
- Myth: exporting a PDF to images and back to PDF redacts it. Reality: the underlying text is gone, but you also lose searchability, accessibility, and selectable text everywhere. Use redaction tools instead.
- Myth: redaction removes the text from the file size. Reality: the rectangle is added on top of the content stream in the redaction pass. File size barely changes.
- Myth: redaction is enough to anonymise a document. Reality: remember to also strip metadata (title, author, keywords) and watch for embedded thumbnails or revision history. Combine with our metadata editor.