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.

  1. 1FindAnonymizer finds sensitive data in your prompt or file.
  2. 2ReplaceEach item becomes a placeholder, like [NAME_1].
  3. 3SendThe AI only gets the placeholders.
  4. 4AnswerThe AI replies using the placeholders.
  5. 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 Lukas Becker (lukas.becker@example.de, +49 30 1234 5678). 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 Lukas Becker, your union membership does not change your notice period. Call me on +49 30 1234 5678.

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.

AI app
Anonymizer on

Draft a short reply to Anna Schmidt about her refund.

Sent to the AI: Draft a short reply to [NAME_1] about her refund.

Dear Anna Schmidt, your refund is on its way. Kind regards

Where Anonymizer works
AI toolDesktop appBrowser
ChatGPTYesYes
ClaudeYesYes
Microsoft CopilotYesYes
Google GeminiYesYes

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 EU.

PDF · Fictional sample

Referral letter

FromRiverside Clinic[ORG_1]
PatientMaria Rossi[NAME_1]
Date of birth14/03/1988[DATE_1]
Medical record no.00012345[MRN_1]

Dear Dr Klein[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 +49 30 1234 5678[PHONE_1] or write to maria.rossi@example.it[EMAIL_1]. Appointment requested for 9 April.

Original: Referral letter From: Riverside Clinic Patient: Maria Rossi Date of birth: 14/03/1988 Medical record no.: 00012345 Dear Dr Klein, I am referring my patient for a review of her asthma (ICD-10 J45.9). She takes salbutamol daily. Please call her on +49 30 1234 5678 or write to maria.rossi@example.it. Appointment requested for 9 April. What the AI gets: Referral letter From: [ORG_1] Patient: [NAME_1] Date of birth: [DATE_1] Medical record no.: [MRN_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.

Batch mode

Everyday files are anonymised right here, on your computer.

Smart rules.

  • 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/anna and example.com/docs
    After[URL_1] and [URL_2]
  • Bank codes

    Routing numbers, sort codes and other bank codes are anonymised when a bank word is next to them.

    BeforeBank routing no. 123456789
    AfterBank routing no. [ROUTING_1]
  • Secrets

    API keys, tokens and passwords are anonymised and, by default, never put back. You can change this.

    Beforeapi_key=EXAMPLE-7f3a9c2e1b
    Afterapi_key=[API_KEY_1]

Runs quietly.

Anonymizer

On · 12 items anonymised today

Works withChatGPT, Claude, Copilot, Gemini

[illustrative; replace with real app screenshots when available]

Keep your AI. Lose the personal data.