Anonymize your data before sending it to an AI
Priversi detects and masks personal data (names, addresses, emails, IBANs, national insurance numbers…) in your text and documents, then restores the real values in the AI's reply. Everything happens in your browser: use ChatGPT, Claude or Gemini without handing them identifying data.
The anonymization model is downloaded into your browser: your data is never sent to a server
Jean Dupont · jean@acme.fr[a1b2c3-NOM_1] · [a1b2c3-EMAIL_1]The proof: once the page has loaded, turn off your internet connection — anonymization still works. It doesn't depend on any server.
How it works
Your data stays private
In your browser
Detection and masking of sensitive data run locally, right in your browser. Your original text or document is never sent for analysis.
Sent to the AI
Only the anonymised version goes to the AI: each sensitive value is replaced by a token like [a1b2c3-NOM_1]. No real data is transmitted.
Local restoration
You paste the AI's response back and the real values are reinserted — in your browser, from the tokens.
The question that matters
Where does your data go?
One picture to understand it all: three possible destinations — and what happens to your data before it goes there.
Your browser
All the work happens here
The AI you use
ChatGPT, Claude, Gemini…
Our servers
Only if you create an account
Compliance
GDPR and the AI Act: what actually changes
Pasting a document into an AI means transferring personal data to a third-party provider. Priversi cuts that transfer down to what is strictly necessary.
Data minimisation (GDPR, Art. 5)
The GDPR requires processing only the data necessary for your purpose. Summarising a contract or rewriting a letter almost never requires the real names, addresses or reference numbers: Priversi replaces them with tokens before anything is sent.
Pseudonymisation (GDPR, Art. 4(5))
Let's be precise about the wording: because the tokens are reversible on your side, this is pseudonymisation, not irreversible anonymisation. That is exactly what makes it useful — the AI provider sees no identifying data, and you still get a usable result back.
Regulator guidance & the AI Act
European data protection authorities consistently recommend limiting the personal data sent to AI systems, and the EU AI Act tightens data-governance obligations. Masking before sending is the simplest and most auditable measure you can put in place.
Priversi is a technical tool: it replaces neither your records of processing nor your impact assessment, but it implements a protection measure you can actually document.
Use cases
By profession
The same steps whatever the document: detect, mask, send to the AI, restore.
Legal
Redact a contract, a filing or a judgment before asking for a summary or a clause review — without exposing the parties' identities or eroding privilege.
Human resources
CVs, appraisal notes, payslips: have an AI summarise, compare or rewrite them without disclosing the identity of candidates and employees.
Healthcare
Clinical notes and patient records: health data is special-category data (GDPR, Art. 9). Mask identities, dates of birth and patient numbers before any AI is involved.
Finance & accounting
Invoices, statements, client files: IBANs, company registration numbers and contact details are detected and masked before sending.
Public sector
Citizen correspondence, benefit files, complaints: work on the substance with an AI without letting residents' identities leave your organisation.
Customer support
Tickets, emails, verbatim feedback: summarise, triage or analyse without handing over your customers' contact details.
All your formats
Plain text, Office documents and PDF — formatting is preserved and PDFs are truly redacted.
- Texte
- DOCX
- PPTX
- XLSX
What is an account for?
One thing only: finding your conversations on your other devices. It changes nothing about your privacy.
Without an account
- Free, unlimited anonymization
- Everything stays on this device
- No sign-up
With an account
- The same anonymization, in your browser
- Conversations available on all your devices
- Saved anonymized and encrypted — unreadable to us
Either way, your original text and files never leave your browser.
Frequently asked questions
Is my data sent to a server?
No. Detection and masking run 100% in your browser. Your original text or document is never transmitted.
How do I get the real values back in the AI's reply?
Each sensitive value is replaced by a token (e.g. [a1b2c3-NOM_1]). You paste the AI's reply back into Priversi and the real values are reinjected locally.
What types of data are detected?
Names, addresses, emails, phone numbers, IBANs, credit cards, social-security numbers, company IDs, IP addresses and more — with settings to enable or disable each category.
Which file formats are supported?
Text, DOCX, PPTX, XLSX and PDF. Formatting is preserved and PDFs are truly redacted.
Do I need an account?
No, the tool works without an account: everything stays on your device. With an account, your conversations are saved so you can find them on your other devices — but end-to-end encrypted: nobody, not even us, can read them on the server. Your original files never leave your browser.
Does the AI model really run in my browser?
Yes. On your first visit, the detection model (~140 MB) is downloaded and cached by your browser, then runs on your device. That's why anonymization works even offline: your text is never sent to a server for analysis.
Does Priversi make my use of AI GDPR-compliant?
Priversi implements one specific technical measure: minimising the personal data transferred to a third party (GDPR, Art. 5). That is a building block of compliance, not compliance in full — you remain responsible for your lawful basis, your records of processing and informing data subjects. What Priversi changes: a workflow that would otherwise send identifying data to an AI provider becomes defensible and documentable.
Is this anonymisation or pseudonymisation?
Pseudonymisation in the GDPR sense (Art. 4(5)): the tokens are reversible, but only inside your browser and only from a mapping table that never leaves your device. From the AI provider's point of view — receiving only tokens, with no way to resolve them — the text carries no identifying elements. That trade-off is what makes the tool usable: irreversible anonymisation would stop you from getting a usable result back.
Ready to protect your data?
Anonymize your first text or document in seconds — free, no account needed.
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