How to redact a document before pasting it into an AI assistant
Before you paste a contract, letter or report into ChatGPT, Claude, Gemini or Copilot, replace the names and numbers with placeholders such as [PERSON_1]. Here is how to do it in your browser with RedactVault, get a useful answer, and put the real values back.
AI assistants are good at summarising a contract, tidying a letter or pulling the dates out of a report. To do that they need the text, so people paste whole documents into them. When you do, every name, address, account number and case reference in that document goes to the AI provider along with your question.
You can usually get the same answer without sending those details. Replace them with placeholders before you paste, and put the real values back into the answer afterwards. This post shows how, and what to check before you press Enter.
What you share when you paste a document
A pasted document is sent to the AI provider in full. What happens to it next depends on the provider, the plan you are on and your settings: how long it is kept, who can see it, and whether it can be used to improve their models. Those terms vary and change, so read your provider’s current terms rather than relying on a summary. The safest assumption is simple: anything you paste has left your control.
If the document holds someone else’s personal data, such as a client, a patient or an employee, that may also matter under your professional rules or data protection law. Taking the identifying details out before you paste reduces what you share in the first place.
Placeholders work better than black bars for AI
A redaction made for publication blacks out a value and stops there. An AI assistant needs to follow who did what to whom, so a row of black bars makes its answer worse. A placeholder keeps the meaning: [PERSON_1] signed the lease, [PERSON_2] is the guarantor, rent is paid from [ACCOUNT_1].
Good placeholders follow three rules:
- The same value always gets the same placeholder, so the assistant can tell that two mentions are the same person.
- Different values get different placeholders, so two people are never merged into one.
- The placeholder says what kind of value it replaced (a person, an email address, an account number), so the answer still makes sense.
Step by step with RedactVault
RedactVault does this with Prepare for AI. It is free on every plan, and it runs in your browser: your document is processed on your device, and RedactVault sends nothing to an AI and calls no AI itself.
- Open your document in RedactVault. It is processed in your browser, on your device.
- Review the findings. Keep the ones you want replaced and reject the ones that should stay as they are.
- When your redacted copy is ready to download, choose Prepare for AI. Each finding you kept becomes a placeholder such as [PERSON_1], the same one every time it appears. You can mark two findings as the same value, or keep one in clear text.
- Read the check of the prepared text. RedactVault runs its pattern detector over the prepared text again and lists anything it still finds, such as an email address or a phone number, with a button to replace it too.
- Read the text yourself, tick the box to confirm you have, and copy it.
- Paste it into your AI assistant and ask your question.
Getting the real names back
The answer comes back with the placeholders in it. Paste it into the Restore page, and the real values go back in, in your browser. The mapping between placeholders and values stays in the browser where you prepared the text, for 24 hours after you last used it. If the reply will come back later or on another device, save the mapping file when you prepare the text, and load it on the Restore page.
What this does not do
- It is reversible pseudonymisation, not redaction. Anyone with the mapping can turn the placeholders back into the real values, so treat the prepared text as personal data.
- Detection can miss things. The pattern detector looks for identifiers such as email addresses and phone and account numbers; it cannot show that nothing personal is left. Read the text before you paste it.
- Context can still identify someone. A unique job title, a rare diagnosis or a small town can point to one person even without a name.
- It prepares text only. Pictures, attachments and files you upload to the assistant separately are not changed.
- The assistant still receives everything you did not replace.
A short checklist before you paste
- Do you need to paste the whole document, or only the part you are asking about?
- Are names, contact details, account numbers and references replaced?
- Did you read the prepared text, including anything the check still found?
- Is anything identifying left in the context, such as job titles, places or dates?
- Do you have the mapping (in this browser for 24 hours, or as a saved file) to restore the answer?
Prepare for AI is free on every plan at RedactVault.com.
FAQ
Common questions
Is it safe to paste a confidential document into ChatGPT or another AI assistant?
Anything you paste is sent to the AI provider, and what happens next depends on its terms, your plan and your settings. Replacing names, contact details and account numbers with placeholders before you paste reduces what you share. Read the prepared text yourself, because detection can miss things.
Does RedactVault send my document to an AI?
No. Prepare for AI runs in your browser. RedactVault sends nothing and calls no AI. You copy the prepared text and paste it into the assistant yourself.
How do I get the real names back into the AI’s answer?
Paste the answer into the Restore page. The real values go back in, in your browser, using the mapping kept in that browser for 24 hours after you last used it, or a mapping file you saved.
Is a placeholder the same as redaction?
No. A placeholder can be turned back into the real value with the mapping, so the prepared text is still personal data. For a file you share with someone else, use a redacted copy.
RedactVault
Prepare a document for AI, free
Open a document in RedactVault, review what it found, and choose Prepare for AI when your redacted copy is ready. Everything runs in your browser.
Open a documentContinue reading
Related articles
Deep Dive: How to Permanently Remove Sensitive Text, Metadata, and Hidden Data From a PDF
Redacting the visible text is half the job. The other half is everything else the PDF is carrying that you cannot see on the page. This post opens up the file format and shows you where the data hides.
Are Online PDF Redaction Tools Safe? What to Check Before Uploading Sensitive Files
Online PDF redaction tools are convenient. Whether one is safe for a particular file is a different question, and the answer depends less on the brand than on what the tool does and what you are about to give it.
How to Check Whether a PDF Was Redacted Securely Before Sharing It
Most guides on PDF redaction end at "click export." This one starts there. Here is how to tell whether a redacted PDF is actually safe before it leaves your hands.