Anonymize a bank statement before an AI categorises your spending
Download your statement as a CSV from online banking and drop it below. Names of people you paid, employers and other identifying payees become codes; dates, amounts and balances stay readable, so the AI can still sort, total and categorise. Restore its table 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 statement exported as CSV
Date,Description,Amount,Balance
02/10/2026,CARD PAYMENT TO GREENMARKET 2231,-54.20,1830.15
03/10/2026,TRANSFER TO J WHITLOCK REF RENT OCT,-750.00,1080.15
05/10/2026,SALARY FROM BRAMBLEWOOD LTD,2410.00,3490.15
07/10/2026,DIRECT DEBIT STREAMLY,-10.99,3479.16Date,Description,Amount,Balance
02/10/2026,CARD PAYMENT TO NAME-001 2231,-54.20,1830.15
03/10/2026,TRANSFER TO J NAME-002 REF RENT OCT,-750.00,1080.15
05/10/2026,SALARY FROM NAME-003 LTD,2410.00,3490.15
07/10/2026,DIRECT DEBIT NAME-004,-10.99,3479.16The landlord and the employer are coded, and so are the shop and the subscription: the engine does not know those names and codes when in doubt. Transaction types, amounts and balances stay readable. If the AI needs shop names to sort your spending, add them under Adjust → Keep readable.
Statements, CSV and what to keep readable
Asking an AI to sort a year of spending works well, and a statement says a lot: who you pay rent to, who employs you, which clinic you visit. Coding the payees that are people or employers keeps the analysis and drops the identities.
- Export a CSV, not a PDF. Most online banks offer a CSV or Excel download. The free tool does not read PDF statements; a CSV also gives the AI clean columns.
- Remove the account header. Your account number and sort code or IBAN are often in the first rows. Delete them, or check they are coded.
- Keep shops readable on purpose. To categorise spending, the AI needs to see “supermarket” or the name of a chain. List those under Adjust → Keep readable; people and employers stay coded.
The free tool takes up to 1,000 rows, enough for a year of most personal accounts. For business accounts, ledgers and bank reconciliation, the Hidden Tokens app works on whole folders and keeps the same codes from month to month.
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
Why is the shop name coded?
Because it looks like a proper noun the engine does not know, and when in doubt it codes. Add shop names under Adjust → Keep readable if the AI needs them.
Are amounts and balances sent as they are?
Yes. Amounts identify no one and the AI needs them to total and categorise. If a specific amount is identifying in your case, add it under Also code.
Can I drop the PDF statement?
No, the free tool does not read PDFs. Export a CSV from online banking, or copy the lines into the Text tab.
Should I ask an AI for financial advice on this?
This page is about protecting the data you send. What you ask is up to you; an AI is not a regulated adviser.
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.