Anonymize a customer database export before an AI analyses it
Drop a CSV or Excel export from your CRM, shop or billing system. Customer names, emails, phone numbers and customer IDs become codes; plans, cities, dates and amounts stay readable, so the AI can segment, count and spot churn. Restore its table here to see the real customers again.
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: three rows of a customer export
Customer ID,Name,Email,Phone,City,Plan,Monthly spend,Signed up
C-20931,Oliver Brandreth,o.brandreth@example.com,+44 7700 900120,York,Pro,49,2024-03-11
C-20944,Megan Lisle,megan.lisle@example.org,+44 7700 900764,Bath,Basic,12,2025-07-02
C-20958,Ashby & Crane Ltd,accounts@ashbycrane.example,+44 20 7946 0321,London,Team,240,2023-11-28Customer ID,Name,Email,Phone,City,Plan,Monthly spend,Signed up
REF-001,FIRSTNAME-001 NAME-001,EMAIL-001,PHONE-001,York,Pro,49,2024-03-11
REF-002,FIRSTNAME-002 NAME-002,EMAIL-002,PHONE-002,Bath,Basic,12,2025-07-02
REF-003,COMPANY-001,EMAIL-003,PHONE-003,London,Team,240,2023-11-28Each customer's ID, name, email and phone are coded, a company customer included; city, plan, spend and sign-up date stay readable for the analysis. A rare combination, such as the only Team customer in a small town, can still single someone out.
Customer exports: segment the data, not the people
Marketing and sales teams export customers to ask an AI for segments, churn risks or a summary of who buys what. The export is a list of real people with their contact details: exactly what should not leave the company.
- Coded: names, emails, phone numbers, customer and account IDs, company names, addresses and payment details.
- Readable: cities, plans, product lines, amounts, dates and column headers. The AI needs them to group and compare.
- Consistent: one customer keeps one code in every row, so counts, repeat purchases and “top 10 by spend” stay correct.
The free tool handles up to 1,000 rows per file, with a new key each time: if you code two exports separately, the same customer gets different codes. To join several exports, or for larger files, use the Hidden Tokens app, which keeps one key per folder.
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
Can the AI still segment my customers?
Yes. Plans, cities, spend and dates stay readable, and each customer keeps one code across rows. Ask for segments, then restore the AI's table here.
What if my export has more than 1,000 rows?
The free tool stops at 1,000 rows. Filter the export to the segment you need, or use the Hidden Tokens app, which has no limit.
Can I join two coded exports?
Not with the free tool: each file gets a new key, so codes do not match between files. The Hidden Tokens app keeps one key across files for that.
Are company customers coded too?
Yes. Company names, like people's names, are coded, and their emails and phone numbers as well.
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.