Anonymize a text before you paste it into Google Gemini
Paste your text below. Names, addresses, emails, phone numbers and ID numbers become codes such as NAME-001. Give Gemini the coded text, then paste its answer back in the Restore tab: the real names come back on your screen, and Google never received them.
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.
Personal account or Workspace: what changes, and what does not
What happens to a Gemini conversation depends on the account. With Google Workspace, Gemini is covered by your organisation's agreement and your data is not used to train the models. With a personal Google account, the consumer privacy notice applies: depending on your activity settings, conversations can be kept, and Google explains that some may be reviewed by people to improve the service.
In both cases Google receives what you paste. Coding first removes the question of who might read it.
- Code here. Paste the text, press Code it, and read the result. Add anything missed under Adjust.
- Ask Gemini on the codes. “Summarise
FIRSTNAME-001 NAME-001's complaint and draft a reply” works as with the real name. - Restore here. Paste Gemini's answer into the Restore tab of this browser tab.
Gemini in Gmail or Google Docs reads your mailbox and files directly through your Workspace permissions. This tool protects what you paste into a prompt, not what Gemini can already open.
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 Gemini still understand the coded text?
Yes. Codes keep the structure: one person, one code; people and companies have different prefixes; dates and amounts stay readable. Gemini can summarise, translate or draft on the coded text.
Is Gemini in Google Workspace already confidential?
Workspace comes with contractual commitments, including no training on your data. Gemini still receives what you send. Coding first means personal data is never part of it.
Can I upload a coded file to Gemini?
Yes. Use the Word or Excel tab to get a coded copy with a generic file name, then upload that copy.
Is this a Google tool?
No. Hidden Tokens is independent and not affiliated with Google. The same tool works with ChatGPT, Claude and 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.