Redact PDF Online Free — Permanently Remove Sensitive Data
Auto-detect and permanently black out Aadhaar, PAN, phone numbers and more. 100% free, no upload. Redact sensitive info from PDFs in seconds.
About Redact
Redact scans a PDF's text for personal data such as Aadhaar and PAN numbers, card and bank details, phone numbers and email addresses, lets you review every hit, and then burns solid boxes over the ones you keep selected. Each affected page is rebuilt as an image, so the covered text is genuinely gone from the output rather than hidden under a shape.
How to use Redact
- Drop in the PDF. Detection works on the text layer, so digital PDFs (downloaded statements, generated reports) give the best results.
- Under Detection Patterns, switch groups on or off. India IDs, Payment Cards, Bank Details and Contact Info are on by default; Global IDs, Medical / Insurance and Vehicle & License are off.
- Optionally type a name or phrase into Custom Search. It also accepts a regular expression, for example \d{6} for six-digit numbers.
- Click Scan for Sensitive Data. Every match is listed with its page and the pattern that found it.
- Untick false positives, or use the per-group select buttons. Pick the box colour (black by default).
- Redact. Pages with selected matches are flattened to images with the boxes burned in; the result downloads as filename_redacted.pdf.
When it helps
Masking Aadhaar before sharing a copy
UIDAI promotes masked Aadhaar, where only the last four digits show. With India IDs on, the scan finds the 12-digit number; you can redact it fully, or use Custom Search with the first eight digits to cover only those.
Sharing bank statements for a rental or loan
Landlords and lenders want to see income credits, not your full account number, card numbers or UPI IDs. Scan with India IDs, Payment Cards and Bank Details, then keep the balances visible.
Publishing documents with contact details removed
Before posting a circular, judgment or report publicly, remove personal phone numbers and email addresses that were meant only for internal use.
Tips
- Review the list carefully. Several patterns are generic: Bank Account (IN) matches any 9 to 18 digit number, so invoice numbers, dates run together and reference numbers will show up. Untick what should stay.
- Search for names as well as numbers. Patterns find structured data; a person's name, address or signature line needs Custom Search.
- After redacting, open the output and try selecting or searching for a redacted value. On redacted pages nothing should be selectable at all.
- Redaction rasterises affected pages at twice the PDF's base resolution, which is sharp for reading and printing but larger than the original. Compress afterwards if size matters.
- Keep the unredacted original somewhere private. Redaction cannot be undone on the output.
Limitations
- Scanned or photographed pages with no text layer produce no matches, and there is no manual box-drawing mode. Such files need OCR first.
- Matching happens within each text fragment the PDF stores. A number split across lines, or written with unusual spacing or separators, can be missed; always read the pages yourself.
- Box positions are estimated from the average character width of the text run, so boxes on proportional fonts can be slightly wider or narrower than the word. The tool pads each box by a couple of points to compensate.
- Redacted pages become images: their remaining text is no longer selectable or searchable, and links and form fields on those pages are lost. Document properties such as author are not cleared; use Remove Metadata for that.
- Encrypted PDFs should be unlocked first.
What happens to your files
The scan uses PDF.js to read the text layer in your browser, and the redacted file is assembled with pdf-lib on your device. Neither the document nor the detected values are uploaded, and the match list is held only in page memory. The redacted output is stored in the on-device workspace (IndexedDB, files expire after seven days) and downloaded; the original file you added also remains there, so delete it if the device is shared.
Related guides
- How to Mask Aadhaar and Redact PDFs Properly
- How to Strip Hidden EXIF, Author & GPS Metadata from PDFs and Photos Before Sharing
- Why Client-Side WebAssembly Processing is Safer Than Cloud Document Converters
Auto-Detect Aadhaar, PAN, Credit Cards and Phone Numbers
File Studio's redaction tool has 48 built-in detection patterns in seven groups, covering Indian identity documents (Aadhaar, PAN, Voter ID), payment and bank data (card numbers, account numbers, IFSC) and contact details (phone numbers, email addresses). Turn on the groups you want, scan, and every match is listed. You review each detection before applying the redaction, ensuring no false positives are permanently removed.
Permanent Redaction — Cannot Be Reversed or Uncovered
A black rectangle drawn on top of text hides it from the eye but leaves the text in the file, where copy, search or a text extractor still finds it. File Studio avoids that: each page with a selected match is rendered to an image, the boxes are burned into that image, and the image replaces the original page. The covered characters are no longer in the file at all. The trade-off is that redacted pages become pictures — their remaining text can no longer be selected or searched — while pages without matches keep their original text.
Review Every Match Before Redacting
Automated detection sometimes flags content you want to keep visible. File Studio's review interface lets you inspect every detected match individually. Toggle specific matches on or off before applying the final redaction. This two-step workflow — detect first, review second — prevents accidental removal of important information while still saving you the time of manually searching through long documents.
48 Built-In Patterns for India, US, UK and Other Documents
Whether you are processing Indian Aadhaar and PAN documents, US Social Security numbers, or UK National Insurance numbers, File Studio covers common identity and financial number formats. Pattern matching is based on the shape of a number, so expect some false positives to untick during review. The Custom Search box finds any specific word, name, or account number (plain text or a regular expression) that the built-in patterns do not cover.
Frequently asked questions
- How do I redact a PDF online for free?
- Upload your PDF to File Studio, select the patterns you want to auto-detect (like Aadhaar, PAN, phone numbers), scan the document, review matches, and click Redact. The sensitive data is permanently blacked out and your clean PDF downloads instantly.
- How do I remove my Aadhaar number from a PDF?
- Upload the PDF, enable the 'India IDs' detection pattern, and click Scan. File Studio finds all Aadhaar numbers automatically. Review the highlighted matches, then click Redact. The numbers are permanently replaced with solid black rectangles that cannot be removed.
- Is the redaction permanent? Can someone undo it?
- Yes. Every page that has a selected match is rendered to an image with the boxes burned in, and that image replaces the original page. The covered text no longer exists in the file, so it cannot be copied, searched or recovered. Pages with no selected matches are left as they were.
- Can I redact custom text, not just patterns?
- Yes. Type it into the Custom Search box. It accepts plain text or a regular expression, ignores letter case, and every hit appears in the review list next to the pattern matches.
- Does redaction work on scanned Aadhaar card PDFs?
- It works on PDFs with a text layer (including OCR-processed scans). For pure image scans with no text layer the scan finds nothing, because detection reads the PDF's text, and the tool has no manual box-drawing mode — run OCR on such a scan first.
- Are my files uploaded to a server?
- No. File Studio is built on a strict local-first architecture. Every PDF operation — merging, splitting, compressing, redacting — runs entirely inside your browser using JavaScript. Your files never leave your computer. You can even disconnect your internet after the page loads and the tools will continue working perfectly.
- Is File Studio completely free?
- Yes, 100% free with no limits. There are no file size caps, no daily limits, no watermarks added to your output, and no account or email required. All tools are free forever.
- Does it work on mobile and tablet?
- Yes. File Studio is fully responsive and works on Android and iOS browsers. All processing happens locally on your phone's or tablet's hardware.