How Anonymizer works.
Sensitive data is swapped for placeholders before it leaves your computer, then swapped back in the answer.
Five steps, one round trip.
RestoreAnonymizer puts the real data back in the answer.
- 1FindAnonymizer finds sensitive data in your prompt or file.
- 2ReplaceEach item becomes a placeholder, like [NAME_1].
- 3SendThe AI only gets the placeholders.
- 4AnswerThe AI replies using the placeholders.
- 5RestoreAnonymizer puts the real data back in the answer.
Try a sample.
Works the same in Claude, ChatGPT, Copilot and Gemini. Your prompt: Reply to Oliver Hughes (oliver.hughes@example.co.uk, +44 20 7946 0958). Does his union membership change his notice period? What the AI receives: Reply to [NAME_1] ([EMAIL_1], [PHONE_1]). Does his [UNION_1] change his notice period? The answer you see: Dear Oliver Hughes, your union membership does not change your notice period. Call me on +44 20 7946 0958.
Fictional data. Nothing leaves your browser.
Works where you work.
ChatGPT, Claude, Microsoft Copilot and Google Gemini, in their desktop apps or in the browser.
Draft a short reply to Olivia Bennett about her refund.
Sent to the AI: Draft a short reply to [NAME_1] about her refund.
Dear Olivia Bennett, your refund is on its way. Kind regards
| AI tool | Desktop app | Browser |
|---|---|---|
| ChatGPT | Yes | Yes |
| Claude | Yes | Yes |
| Microsoft Copilot | Yes | Yes |
| Google Gemini | Yes | Yes |
Works in English and all EU languages.
The same short prompt in all 24 EU languages. In every language, the name, the email address and the IBAN become [NAME_1], [EMAIL_1] and [IBAN_1].
Files and big batches.
Everyday files are anonymised on your computer. Big batches run in the cloud of your choice, in the UK.
PDF · Fictional sample
Referral letter
Dear Dr Patel[NAME_2], I am referring my patient for a review of her asthma[HEALTH_1] (ICD-10 J45.9[ICD10_1]). She takes salbutamol[MEDICATION_1] daily.
Please call her on +44 161 496 0456[PHONE_1] or write to sarah.mitchell@example.co.uk[EMAIL_1]. Appointment requested for 9 April.
Original: Referral letter From: Riverside Surgery Patient: Sarah Mitchell Date of birth: 14/03/1988 NHS number: 999 123 4578 Dear Dr Patel, I am referring my patient for a review of her asthma (ICD-10 J45.9). She takes salbutamol daily. Please call her on +44 161 496 0456 or write to sarah.mitchell@example.co.uk. Appointment requested for 9 April. What the AI gets: Referral letter From: [ORG_1] Patient: [NAME_1] Date of birth: [DATE_1] NHS number: [NHS_1] Dear [NAME_2], I am referring my patient for a review of her [HEALTH_1] (ICD-10 [ICD10_1]). She takes [MEDICATION_1] daily. Please call her on [PHONE_1] or write to [EMAIL_1]. Appointment requested for 9 April.
Everyday files are anonymised right here, on your computer.
Smart rules.
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Dates
Birth dates and document dates are anonymised when a word like ‘DOB’ is next to them. Meetings and deadlines stay.
BeforeDOB: 14 March 1988. Meeting: 12 March.AfterDOB: [DATE_1]. Meeting: 12 March. -
Links
Every link is anonymised. A profile link and a docs link look the same.
Beforeexample.com/u/olivia and example.com/docsAfter[URL_1] and [URL_2] -
Bank codes
Sort codes, routing numbers and other bank codes are anonymised when a bank word is next to them.
BeforeBank sort code 12-34-56AfterBank sort code [SORT_CODE_1] -
Secrets
API keys, tokens and passwords are anonymised and, by default, never put back. You can change this.
Beforeapi_key=EXAMPLE-7f3a9c2e1bAfterapi_key=[API_KEY_1]
Runs quietly.
AnonymizerOn · 12 items anonymised today
[illustrative; replace with real app screenshots when available]