Built for legal professionals

Your clients' data stays
private when you
use AI.

PrivyMask strips and pseudonymises personally identifiable information from legal documents before they reach any AI tool — then restores the original names in the AI's response. Your document is processed in memory and never stored.

Start free — 1 document included See how it works →

Never stored on diskAligned with Data Protection LawsSRA guidance compliant

document.pdf

mapping_key.json

Original — contains PII

Dear Sarah Thornton,

Further to our call on 14 March 2025, I write in the matter of Thornton v Meridian Holdings Ltd.

Your NI number AB123456C and address at 42 Clifton Parade, Bristol BS8 4QJ are on file.

Pseudonymised — safe for AI

Dear PERSON_A,

Further to our call on DATE_1, I write in the matter of PERSON_A v ORG_1.

Your NI number ID_1 and address at ADDR_1 are on file.

Your document is processed in memory and never stored. The mapping key never leaves your device.

How it works

Four steps.
Total control throughout.

Unlike black-box redaction tools, you see exactly what's detected and approve every change before processing begins.

Upload your document

Drop a PDF, Word doc, or scanned image. OCR handles handwritten or image-based files automatically. Your document is processed in memory and never written to disk.

Review detected PII

PrivyMask scans for names, ID numbers, addresses, dates, case references and more. You approve or dismiss each item before anything is replaced.

Get clean text + key

Download pseudonymised markdown to paste into Claude or ChatGPT, plus an encrypted mapping key — generated locally, never sent to us.

Restore real names

Paste the AI's response back into PrivyMask with your mapping key. Real names are restored automatically — your final output is complete and accurate.

The mapping key is yours alone. It's generated in your browser using AES-256-GCM encryption and downloaded directly to your device. PrivyMask never receives it, cannot access it, and cannot be compelled to produce it. If you lose it, the pseudonyms cannot be reversed — this is a feature, not a limitation.

Features

Built specifically for
legal practice.

Generic anonymisation tools don't know what a case reference number is. PrivyMask does.

Document support

PDF, DOCX & scanned images

Court bundles, client letters, attendance notes, witness statements. Native PDFs, Word files, and scanned documents via OCR — all handled without plugins or installs.

Detection

Comprehensive PII detection

Names, addresses, national ID numbers, postcodes, phone numbers, dates, email addresses, case references — plus natural language names in prose.

Privacy architecture

No data retention

Your document is processed in memory and never written to disk. The mapping key is generated in your browser and never sent to our servers. Nothing is retained after your session ends.

Workflow

Reversible pseudonymisation

Unlike permanent redaction, pseudonyms preserve document meaning. The AI gives you a coherent response. You restore real names in one click. Full round-trip workflow.

Professional control

Human review step

You approve every detected entity before processing. Confidence scores surface borderline detections. You can add missed items manually. No silent replacements, ever.

Coverage

Global PII categories

UK, US, EU, Australian, Indian and Singaporean identifiers — NI numbers, SSNs, postcodes, TFNs, Aadhaar and more. Plus Article 9 sensitive categories: health, religion, political affiliation, criminal allegations.

Pricing

Start free.
Upgrade when you're ready.

No contracts. Cancel any time. All plans include the full pseudonymisation pipeline and mapping key.

MonthlyAnnual

Starter

Try it risk-free, no card required

Free / forever

1 free document
Then £2/doc (top-up packs)
PDF, DOCX and image support
Full PII detection
Encrypted mapping key download
Restore AI output workflow

Start free — 1 doc

Your clients' data staysprivate when youuse AI.

Four steps.Total control throughout.

Built specifically forlegal practice.

Start free.Upgrade when you're ready.

Your clients' data stays
private when you
use AI.

Four steps.
Total control throughout.

Built specifically for
legal practice.

Start free.
Upgrade when you're ready.