Anonymize a WhatsApp or Slack conversation before an AI summarises it
Paste a chat below, or drop a WhatsApp export (.txt). Every sender, every person mentioned and every phone number shown for an unsaved contact becomes a code; timestamps and the conversation itself stay readable. Ask the AI for the summary or the to-do list on the codes, then restore it here.
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.
Example: four lines of a WhatsApp export
12/10/2026, 09:14 - Rosa Delgado: Morning! Did the plumber come to number 38?
12/10/2026, 09:16 - Ben Ashworth: Yes, the boiler needs replacing, £1,900
12/10/2026, 09:17 - +44 7700 900877: Hi, it's Kevin from Brightside, the heating firm, I can do Thursday
12/10/2026, 09:20 - Rosa Delgado: Ben, can you tell the tenant, Mrs Pellegrino?12/10/2026, 09:14 - FIRSTNAME-001 NAME-001: Morning! Did the plumber come to number 38?
12/10/2026, 09:16 - FIRSTNAME-003 NAME-002: Yes, the boiler needs replacing, £1,900
12/10/2026, 09:17 - PHONE-001: Hi, it's FIRSTNAME-002 from NAME-003, the heating firm, I can do Thursday
12/10/2026, 09:20 - FIRSTNAME-001 NAME-001: FIRSTNAME-003, can you tell the tenant, Mrs NAME-004?Each sender keeps one code from line to line, the unknown sender's phone number is coded, and so is the tenant mentioned in passing. The heating firm's name is coded, what it does stays readable: the AI still follows the conversation.
Getting a chat out, and what to check
Group chats are where work happens and where people say the most: home addresses, phone numbers, who is ill, who is late paying. Pasting one into an AI sends every participant, including those who never agreed to it.
- WhatsApp: in the chat, More → Export chat → Without media gives a .txt file. Drop it in the Word or Excel tab, or paste its content. Each line starts with a date and the sender's name, or a phone number if the contact is not saved: both are handled.
- Slack or Teams: copy the thread from the app and paste it. A full Slack workspace export is a set of JSON files: paste the messages you need rather than the whole archive.
- Long chats: the free tool codes up to 3,000 words at a time, roughly a few weeks of an active group. Keep the period you need.
Read the coded text before sending: nicknames, initials and in-jokes can identify someone without a full name, and the engine cannot know that “the big boss” is one person.
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 it handle the WhatsApp export format?
Yes. Dates and times at the start of each line stay readable, sender names and phone numbers are coded. Codes are consistent, so the AI can tell who said what.
What about photos and voice notes?
Export without media. Photos and voice notes are not text: the free tool cannot code them, and they are better left out of what you send to an AI.
Can I code a Slack JSON export?
Paste the messages you need as text. A JSON archive full of user IDs and metadata is closer to a log file; see our page on logs and JSON.
Do I need the participants' consent?
This tool does not answer that question for you. Coding removes their names and numbers from what the AI receives, which reduces what is shared about them.
Other ways to use the free tool
By file type
By AI tool
By task
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.