A black rectangle can hide text on screen without removing the text stored inside a PDF. Someone may still be able to select, copy, search, or recover what appears to be covered.
That gap is why I built RedactGo, a free PDF redaction tool that runs locally in the browser.
The problem I wanted to solve
People often need to share contracts, invoices, forms, or reports while removing names, contact details, reference numbers, signatures, or image regions.
The easy-looking solution is to draw a black box over the sensitive area. But a visual overlay and actual redaction are different operations. A safer workflow should create a new output file and let the user inspect that result before sharing it.
What RedactGo does
With RedactGo, you can:
- open one PDF up to 10 MB
- draw multiple redaction areas across multiple pages
- undo marks or redact an entire page
- generate a new PDF
- review the actual generated output before downloading
- keep unmarked text searchable where the document allows it
There is no account, no daily limit, and no watermark.
The output step also removes basic metadata and embedded-file entries for supported documents.
Why it runs in the browser
PDF documents can contain private or regulated information. I wanted the default workflow to avoid sending the document to an application server.
The preview and redaction work in the browser. PDF.js handles viewing, while MuPDF.js runs the redaction work in a background worker. The PDF bytes are not uploaded to a RedactGo document server.
Analytics is deliberately separate from document processing: it records page views and a small set of tool events, without PDF filenames, text, or redaction coordinates.
Failure should look like failure
One design choice mattered more than adding another feature: if the tool cannot safely process a document, it should not produce a download that looks successful.
RedactGo therefore refuses some PDFs with unsupported features, including encrypted files and certain interactive, tagged, layered, or scripted documents. This is less convenient than accepting everything, but it is more honest than showing a green success state for an output that was not safely rewritten.
It is also why the result preview displays the actual output PDF rather than a mock preview of the original page with boxes on top.
Current limits
RedactGo is useful for a focused task, but it is not a universal PDF security guarantee.
- one file at a time
- maximum file size of 10 MB
- complex PDFs may be rejected
- users still need to review every page of the downloaded result
- metadata cleanup cannot automatically discover every kind of sensitive information
Those limits are shown because privacy tools should make uncertainty visible.
Open source
RedactGo is licensed under AGPL-3.0-or-later. The application source, license information, third-party notices, and corresponding MuPDF source details are available on the source and licenses page.
You can try the tool here:
👉 Redact a PDF in your browser with RedactGo
I would especially appreciate feedback on the editing workflow, output review step, and PDF compatibility.
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