Anonymize text and files before ChatGPT or Claude
Paste a text or drop a Word or Excel file. Every name, company, address, email, phone, bank and ID number becomes a code such as NAME-001. Send the coded version to the AI, then paste its answer back here: the real names return, in this tab only. Free, no account, nothing leaves your browser.
Restoring uses the key of this tab: code your text here first, keep this tab open, then come back with the answer.
Adjust
See the key (it stays in this tab)
The key links each code to the real value. It exists only in this tab's memory: close or reload the tab and it is gone.
connect-src 'none' in its security policy) and loads no analytics. Turn Wi-Fi off once the page has loaded: the tool works just the same. The engine is the one inside the Hidden Tokens app.How it works
1 · Code
Paste a text or drop a file. Names, companies, addresses, emails, phone numbers, bank details, ID and case numbers become codes such as NAME-001 or COMPANY-001. Unknown proper nouns are coded too: when in doubt, the engine codes.
2 · Send the codes
Copy the coded text, or download the coded file, and give it to ChatGPT, Claude, Gemini or Copilot. The AI reasons on the codes: it still knows who did what, not who they are.
3 · Restore
Paste the AI's answer in the Restore tab, in the same browser tab. The codes become the real names again, on your screen only.
What gets coded, and what stays readable
The engine is the one in the Hidden Tokens app. It codes what identifies someone and leaves the rest readable, so the AI can still do its job:
- Coded: first names and surnames, companies, postal addresses, emails, phone numbers, IBANs and bank cards, ID, passport and company registration numbers, case and file references, and any proper noun it does not know.
- Readable: ordinary words, dates, and amounts. An amount identifies no one, and the AI needs it to calculate.
The same value always gets the same code in one run: if Daniel Okafor appears five times, the AI sees FIRSTNAME-001 NAME-001 five times and can follow him through the text.
The free tool or the Hidden Tokens app?
This free tool
- One text or one file at a time
- Up to 3,000 words or 1,000 spreadsheet rows
- The key lives in this tab and disappears when you close it
- Word, Excel, CSV and text
The Hidden Tokens app
- Whole folders: the same person keeps the same code in every document
- One key per case file, kept on your computer
- PDF and scanned documents, read on your computer
- Inside Claude Desktop, and in ChatGPT, Gemini and Copilot with the extension
- Industry packs, firm rules and a signed proof of what the AI saw
A word on the word “anonymize”
Strictly speaking, this tool pseudonymizes: each value is replaced by a code that can be reversed with the key. Under the GDPR, pseudonymised data is still personal data for whoever holds the key, which here is you, in this tab. What the AI receives no longer names anyone directly. Clues can remain, such as a job, a town and an age together: the tool warns you when it sees them. Read the result before sending it.
Questions
Is this tool really free?
Yes. No account, no card, no limit on the number of uses. It handles one text or one file at a time, up to 3,000 words or 1,000 spreadsheet rows. For whole folders, the Hidden Tokens app offers a 14-day free trial.
Is my text sent anywhere?
No. The page forbids the browser from opening any connection and loads no analytics. You can turn Wi-Fi off after the page has loaded and the tool keeps working.
Which AI tools does it work with?
Any of them: ChatGPT, Claude, Gemini, Copilot, Mistral or an internal model. You copy the coded text where you want; the AI only ever sees codes.
What happens if I close the tab?
The key disappears with it, so the AI's answer can no longer be restored here. Keep the tab open between coding and restoring. The Hidden Tokens app keeps one key per case file on your computer.
Other ways to use the free tool
For whole folders, use the app
Hidden Tokens codes whole case files on your computer with one key, works inside Claude Desktop and in your browser, reads PDFs and scans, and puts the real names back into Word and Excel files.