Your step-by-step guide to redacting sensitive data from PDFs safely and securely.
Tip
This takes about 5 minutes. New to PDF redaction? Start with Step 1 below.
| 🎯 Step | ⏱️ Time | What You'll Do |
|---|---|---|
| 1️⃣ Load | 30 sec | Open a PDF file |
| 2️⃣ Configure | 30 sec | Select document language |
| 3️⃣ Auto-Redact | 1-2 min | Run AI to find sensitive data |
| 4️⃣ Review | 1-2 min | Manually fix any mistakes |
| 5️⃣ Blindfold | 30 sec | Hide images (optional) |
| 6️⃣ Export | 30 sec | Save the redacted PDF |
- Click the blue "Apri PDF" button in the top left
- Select a PDF file from your computer
- The document appears in the center. Scroll with mouse or use arrow buttons (top right)
Note
Supported format: unencrypted PDF. Digital text is scanned directly; scanned pages require OCR.
Before scanning, select your document's language from the left sidebar:
| 🌐 Language | Use When |
|---|---|
| EN | Document is entirely in English |
| IT | Document is entirely in Italian |
| BOTH | Document contains mixed languages |
Warning
Wrong language = missed detections. Choose the exact language of your document.
Click the "Auto Redact (AI)" button. NullifyPDF will automatically find and flag:
- 🧑 Names & Surnames
- 🏙️ Cities & Addresses
- 📧 Email Addresses
- 📱 Phone Numbers
- 💳 IBANs & Credit Card Numbers
- ₿ Cryptocurrency Addresses
What to expect:
- Black boxes appear over detected data
- Progress bar shows scanning progress
- On large PDFs (500+ pages): 30-60 seconds normal
- UI stays responsive (no freezing)
Tip
The AI isn't perfect. You'll review results in Step 4.
No AI is 100% accurate. You can fix mistakes:
Draw a box over text you want to hide:
- Click and drag mouse over sensitive text
- A black box appears
- Redaction is scheduled (not destructive yet)
Click once on a black box to remove it:
- Single click on the redaction box
- Box disappears
- Word is added to Allowlist (AI will ignore it next time)
Make small text larger:
- Press + / - keys, OR
- Hold CTRL + Mouse wheel up/down
Important
Changes are preview only until you export. You can undo everything before export.
Remove logos, signatures, or scanned photos:
- Enable the toggle: "Oscura Immagini" (sidebar)
- Click "Auto Redact (AI)" again
- All images replaced with gray placeholder:
[ IMAGE REMOVED ]
Note
For scanned documents, enable OCR PDF scansionati before running the AI scan. Full builds include EN/IT OCR data; Lite builds require local Tesseract tessdata.
When satisfied with redactions:
- Click "Esporta Privacy"
- Choose the export mode:
- Anonimizzazione irreversibile removes selected personal data permanently
- Pseudonimizzazione reversibile replaces selected personal data with placeholders and creates a separate encrypted restore map
- Choose filename and location
- Review the exported PDF before sharing it
Caution
Irreversible anonymization cannot be undone from the exported PDF. Keep a backup of the original PDF. For pseudonymization, store the encrypted restore map separately from the PDF.
Your redaction preferences are saved automatically:
| OS | Path |
|---|---|
| Windows | C:\Users\<username>\.nullifypdf\ |
| macOS | ~/.nullifypdf/ |
| Linux | ~/.nullifypdf/ |
.nullifypdf/
├── blocklist.txt ← Words to ALWAYS redact
├── allowlist.txt ← Words to NEVER redact
├── logs/
│ └── nullifypdf.log
📝 Edit Blocklist/Allowlist Directly
- Open file manager, navigate to
~/.nullifypdf/ - Edit
blocklist.txtorallowlist.txtwith any text editor - One word per line, UTF-8 encoding
- Restart NullifyPDF to load changes
Example blocklist.txt:
john smith
acme corporation
[email protected]
The manual redaction workflow keeps clicked/drawn terms mutually exclusive. When editing dictionary files or the dictionary dialog directly, review both lists and avoid adding the same term to both.
- Backup Original — Always keep the original PDF before redacting
- Test on Copy — Redact a test copy first, verify results
- Verify Export — Open exported PDF to confirm redactions look correct
- Choose Language Carefully — Wrong language = missed detections
- Use Allowlist Sparingly — Only add words you're 100% sure aren't sensitive
Log files track all activity. Location:
| OS | Path |
|---|---|
| Windows | C:\Users\<username>\.nullifypdf\logs\nullifypdf.log |
| macOS/Linux | ~/.nullifypdf/logs/nullifypdf.log |
2026-06-06 14:23:45 - INFO - Loaded PDF: document.pdf
2026-06-06 14:23:50 - INFO - AI scan complete: 5 detections
2026-06-06 14:24:10 - ERROR - Export failed
For detailed troubleshooting, enable verbose logging:
🔍 Windows (PowerShell)
$env:NULLIFYPDF_DEBUG = "true"
python NullifyPDF.py🔍 macOS/Linux (Bash)
export NULLIFYPDF_DEBUG=true
python3.13 NullifyPDF.pyEffect: Debug logs include full stack traces. Useful when reporting bugs.
- Encoding: UTF-8
- Location:
~/.nullifypdf/logs/nullifypdf.log - Rotation: not currently implemented; remove old logs manually if needed
A: Enable OCR PDF scansionati before running the AI scan. Full builds include EN/IT OCR data; Lite builds need local Tesseract tessdata.
A: Not built-in. Use a PDF editor after export for password protection.
A: Export applies PDF redactions and removes selected metadata. Review the exported file before sharing, especially for high-risk documents.
A: Irreversible anonymization cannot be undone from the exported PDF. Pseudonymization can be restored only with the encrypted restore map and its password.
A: No. PDF processing is local. Full builds may download OCR data during build time, not while processing your PDFs.
- ✅ Ready to use? Start with Step 1 above
- 🐛 Stuck? See TROUBLESHOOTING.md
- 👨💻 Want to contribute? Read CONTRIBUTING.md
- 🏗️ Curious about architecture? Check ARCHITECTURE.md
Last updated: 2026-07-23
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