Your team already uses AI on client documents. The question is which data goes in with them. This guide shows how to ask ChatGPT, Claude or Copilot to review a contract without the identity numbers, emails or party names ever leaving your computer.
A contract or case file pasted into an AI chat carries everything it contains: the parties’ ID numbers, emails, bank accounts and addresses. Your client trusted that data to you, not to a third-party tool.
Deleting it by hand is not enough. It takes time on every document, and something almost always slips through on page fourteen. Privacy rules such as the GDPR in Europe expect you to protect other people’s personal data.
Want to see what a text contains before sending it? Paste it into the free personal data detector. It runs in your browser and nothing is uploaded.
Because the data is replaced with placeholders (for example “ID 1”), the AI can reason about the contract without knowing whose data it is. And the same placeholder always stands for the same person across all of a client’s documents.
With no setup it hides ID numbers from 32 countries (DNI and NIE, CURP and RFC, CPF, RUT, CUIT, NIT and more), emails, phone numbers, cards and bank accounts.
With you, once: your clients’ and companies’ names (you add them and they are hidden in every document) and the fields in your own forms, such as “Address” or “Case file”.
What it does not do by itself is recognise a name inside a paragraph. That is why it shows you what is still visible before you copy, and you hide it by selecting it.
With the data hidden, the AI works on the structure and legal content of the document, which is what you need from it.
Every conversion with hidden data leaves a dated record: what was hidden, in which files, when and on which computer. It never stores the original values. If you later need to show how you handled a client’s data, that record exists.
No. ContextDeck reduces the risk of exposing personal data when you use AI and keeps a record of what you did. It is not legal advice and does not replace the legal review your own jurisdiction requires.
Yes. It accepts PDF, Word, Excel and PowerPoint. With Pro it also handles whole folders, scanned PDFs and photos.
No. The record shows what was hidden, in which files, when and on which computer, but never the original values.
The Free plan marks the personal data it finds but does not hide it. Hiding it before you copy is part of Pro, which you can try for 14 days without a card.
ContextDeck reduces the risk of exposing personal data when you use AI and keeps a record of what you did. It is not legal advice and does not replace the legal review your own jurisdiction requires.
Try Pro free for 14 days, no card. You download the Windows app and nothing is uploaded to the internet.
Download for Windows