Anonymize a text before you paste it into ChatGPT
Paste your text below. Client names, companies, emails, phone numbers and bank details become codes such as NAME-001. Paste the coded text into ChatGPT, then paste ChatGPT's answer back in the Restore tab: the real names come back on your screen. Nothing is sent to OpenAI that names your client, and nothing is sent to us at all.
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.
The safe way to use ChatGPT with client information
Even on a paid plan, what you paste into ChatGPT is received and kept by OpenAI under its own retention rules. Settings such as Improve the model for everyone change whether it trains on your data, not whether it receives it. The only way to be sure a client's name is not in ChatGPT is to never send it.
- Code before you paste. Paste your email, notes or clause above and press Code it. Check the coded text: anything the engine missed can be added under Adjust.
- Ask your question on the codes. “Draft a reply to
FIRSTNAME-001 NAME-001refusing the new deadline” works exactly as with the real name. - Restore the answer here. Copy ChatGPT's reply into the Restore tab of this same browser tab. If ChatGPT rewrote a code, for example in lower case, the tool tells you how many codes it could not restore.
Doing this every day? The Hidden Tokens browser extension does it inside ChatGPT itself: each message is coded before it is sent and the answer is translated back on screen.
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
Does ChatGPT still understand the text?
Yes. Codes keep the structure: the same person always has the same code, companies and people have different prefixes, and dates and amounts stay readable. ChatGPT reasons on who did what, without knowing who they are.
Can I upload the coded text as a file to ChatGPT?
Yes. Use the Word or Excel tab to get a coded copy of the file, with a generic file name, since a file name can contain a client's name.
Does turning off chat history protect client data?
It limits what is kept and used for training, but ChatGPT still receives the text. Coding it first means the client's identity is never in the message.
Is this an official OpenAI tool?
No. Hidden Tokens is independent and not affiliated with OpenAI. The tool works the same with Claude, Gemini or Copilot.
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.