Anonymize Text (Redact Personal Data)
Hide personal data before sharing text: emails, phone numbers, links, IP addresses, card numbers, IBANs, US SSNs, dates and listed names, as tags or placeholders.
Everything runs in your browser; the text is not sent anywhere. Rules can miss data in unusual formats (street addresses, account numbers, names you did not list), so read the result before you share it.
| Type | Original | Replaced with | Times |
|---|---|---|---|
| NAME | Maria | [NAME_1] | 2 |
| PHONE | +1 (415) 555-0132 | [PHONE_1] | 1 |
| tom.baker@example.com | [EMAIL_1] | 2 | |
| CARD | 4111 1111 1111 1111 | [CARD_1] | 1 |
| IP | 203.0.113.42 | [IP_1] | 1 |
| URL | https://shop.example.com/order/8812 | [URL_1] | 1 |
Before you paste a log file, a support ticket or an email thread into a forum, a bug report or a chat tool, take the personal data out. This tool finds email addresses, phone numbers, links, IP addresses, payment card numbers, IBANs, US Social Security numbers, dates and any names you list, and replaces them with tags, numbered placeholders, black bars or partly masked values. Numbered placeholders keep the text readable: every mention of the same person or address gets the same label.
How to use this tool
- Paste the text.
- Tick the kinds of data to hide and list any names, company names or other words that must go.
- Choose the replacement: numbered placeholders, simple tags, black bars or partial masking.
- Copy the anonymized text. Keep the replacement table to yourself if you need to map the placeholders back later.
Formula
Card numbers: Luhn check digit · IBAN: (account moved behind its country code, letters → 10–35) mod 97 = 1
Card numbers are 13–19 digits with optional spaces or dashes that pass the Luhn formula, so order numbers rarely match. IBANs must pass the ISO 13616 mod-97 check. Phone numbers need 7–15 digits and either a + sign, separators or at least 10 digits; dates, IP addresses and decimals are excluded. IPv6 addresses are validated group by group. Social Security numbers must use the 123-45-6789 layout and skip the never-issued 000, 666 and 9xx areas. Where two matches overlap, the more specific one wins, so a name inside an email address is replaced as part of the email.
Example
In the sample, numbered placeholders give “Hi [NAME_1], please call me on [PHONE_1] or write to [EMAIL_1].” The card becomes [CARD_1], the server address [IP_1] and the shop link [URL_1]. The email address appears twice and both copies become [EMAIL_1]; “Maria” on the last line is [NAME_1] again. Dates are off by default, so 2026-03-14 stays.
Frequently asked questions
Is my text uploaded?
No. Detection and replacement run in your browser with plain pattern matching, so the text and the replacement table stay on your device.
Why are names not found automatically?
Telling a name from an ordinary word needs a dictionary of every name in every language, and still fails on names like Rose or Hope. Listing the names you care about is far more reliable.
Is this enough to anonymize data under GDPR?
Replacing direct identifiers is pseudonymization, not full anonymization: details left in the text, such as a job title and a city, can still identify someone. Use it to share snippets safely, and follow your organisation’s rules for real datasets.
Last updated:
Page address with these inputs: https://kakao.mobile/tools/anonymize-text-tool/
Cite or embed this tool
kakaoCalc. (2026, November 8). Anonymize Text (Redact Personal Data). https://kakao.mobile/tools/anonymize-text-tool/
“Anonymize Text (Redact Personal Data).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/anonymize-text-tool/.
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