Redact a PDF for free —
online, auditable, permanently removed
Upload a PDF and the AI automatically detects names, IBANs and email addresses. Redact with one click — irreversible, on EU servers, with an audit log. No sign-up, up to 5 pages free.
WHAT THE FREE CHECK DETECTS
Redact a PDF — without compromising on data protection
Free online redaction is available in many places. Datenmaske goes a step further: processing with primary hosting in Germany, automatic AI detection instead of manual masking, irreversible text removal and an audit log for your GDPR file.
Primarily hosted in Germany
The application and the regular NER run on infrastructure in Germany. For OCR and optionally as an NER fallback stage, Datenmaske uses Azure in configured EU regions with a DPA. OpenAI and Google do not receive any document contents.
Automatic AI detection
Named Entity Recognition (NER) plus regex patterns automatically detect names, IBANs, email addresses, phone numbers, addresses and more than 10 other data types.
Irreversible with MuPDF
The text is physically removed from the PDF, not just visually covered. No copying, no reconstruction — unlike a simple black bar.
Audit log for GDPR proof
Every redaction is logged: what, when, where and by whom. This lets you demonstrate compliance with GDPR Art. 5(2) (accountability).
Datenmaske vs. pdf24, smallpdf, iLovePDF
Free PDF redaction is offered by several providers. The comparison shows: anyone who has to work in a privacy-compliant way needs more than a black bar — automatic detection, EU hosting and an audit log are decisive.
| Criterion | Datenmaske | PDF24 | Smallpdf | iLovePDF |
|---|---|---|---|---|
| EU hosting available | ||||
| Automatic AI detection (NER + regex) | ||||
| Irreversible text removal | partial | partial | ||
| Audit log / redaction protocol | ||||
| Server location Germany | ||||
| Clean metadata (bookmarks, comments) | limited | |||
| Free use without sign-up | up to 5 pages | limited | limited |
Comparison: Datenmaske (Free Check + registered accounts), PDF24 Tools (free online version), Smallpdf (free version), iLovePDF (free version). As of: July 2026, without warranty.
What does “redact a PDF” actually mean?
Redacting a PDF means removing personal or confidential text passages from a PDF document irreversibly . The text is physically deleted from the file's content stream and replaced with an opaque area — it can then neither be read nor reconstructed.
Many users simply place a black bar over the text and consider that redaction. That is a mistake: the text remains in the PDF file and can be made visible again by copying, in text editors or by removing graphic layers. A sample of publicly indexed PDFs found selectable text under the manual redaction in roughly every sixth document (approx. 17 %).
The GDPR requires appropriate technical and organisational measures for processing personal data (Art. 32 DSGVO). When passing on documents, irreversible redaction is the most reliable measure — visual overlay is insufficient both legally and technically.
More on this in the detailed guide to GDPR-compliant PDF redaction and in the blog post Redacting documents .
Redact a PDF for free in 3 steps
From upload to a redacted PDF in under two minutes — no sign-up, no installation, right in the browser.
Upload PDF
Upload a PDF via drag & drop (max. 5 pages, 10 MB in the Free Check). No sign-up required. The file is processed encrypted on EU servers.
Review suggestions
The AI automatically detects names, IBANs, email addresses, phone numbers and other personal data. Confirm or reject each suggestion individually.
Export redacted PDF
Export with one click. The original text is irreversibly removed from the PDF — not just covered. Watermarked look in the free Free Check.
Questions about free PDF redaction
Can I really redact a PDF for free?
Yes. The Datenmaske Free Check lets you scan a PDF of up to 5 pages without signing up and export it once for free. Automatic detection (names, IBANs, email addresses, phone numbers and more) is included. A free account is required for repeated exports, OCR for scanned documents and unlimited pages.
Does the free PDF redaction support GDPR processes?
Yes, as a technical tool: the export removes confirmed text passages from the PDF content and cleans metadata; the log supports documentation. The responsible party must check the legal basis, selection of passages and result themselves. Hosting and Azure details are in the privacy policy and DPA.
What is the difference between Datenmaske and pdf24?
PDF24 offers free online redaction but is not specialised in GDPR compliance. Datenmaske differs in three points: (1) automatic AI detection instead of exclusively manual marking, (2) a complete audit log for GDPR proof and (3) cleaning of metadata (bookmarks, comments, PDF properties) that is often overlooked with pdf24.
Is a black bar in the PDF enough?
No. A black bar only covers the text visually — the original text remains in the PDF file's content stream and can be restored by copying (Ctrl+C), opening it in a text editor or removing the graphic layer. A sample of publicly indexed PDFs (Essex Software, n=72) found selectable text under the manual redaction in roughly every sixth document (approx. 17 %). Real redaction removes the text irreversibly.
Are my documents stored?
In the Free Check, documents are only processed temporarily and deleted after analysis. There is no permanent storage without an account. Registered users choose a retention period within their plan limit; the default is 30 days from upload.
Which data is detected automatically?
AI detection combines regex patterns (for IBAN, email, phone, social security number, credit card number) with Named Entity Recognition (NER) for names, places and organisations. Addresses and dates of birth are also detected. Registered users get OCR for scanned documents and can create custom patterns.
Is the redaction really irreversible?
Yes. Datenmaske physically removes the text from the PDF content stream via MuPDF (applyRedactions) and replaces it with an opaque area. The exported PDF no longer contains any copyable text at the redacted positions — not in text editors, not after removing graphic layers and not through forensics tools.