Redact text online without uploading it
Most "redact online" tools are built for PDFs, and most of them upload the document to a server to do it. For plain text, a chat message, an email or a snippet of a report, you can redact in the browser instead, so the text that needs redacting never travels anywhere.
Redacting vs. replacing
Redaction removes a value and leaves a visible gap. In the Anonymizer that is the Mask mode: every value becomes asterisks of the same length, so the layout of the text stays the same and nothing can be restored. If the text is still meant to be read or answered, the other modes may suit better: placeholders such as [PERSON_1] keep who-is-who, fake data keeps the text natural.
Step by step
- Open the anonymizer and paste the text, or open a TXT, CSV, JSON or log file. It is read by your browser, not uploaded.
- Choose Mask under "Replace with".
- Review the findings: names, emails, phone numbers, addresses, dates of birth, IBANs, card numbers, national IDs, keys, IP addresses and URLs are detected. Untick anything that should stay.
- Add terms the rules can't know, such as a company, a project or a customer number, to the custom terms list.
- Copy or download the redacted text.
How to tell a tool really runs in the browser
- Open the browser's developer tools, switch to the network tab and paste some text: no request should carry it.
- Load the page, then disconnect from the network: a local tool keeps working.
- Look for a content security policy that forbids connections. The Anonymizer's editor runs in an isolated frame whose policy allows none at all.
Limits
Detection works on text. Scanned documents and images need OCR first, and a PDF's hidden layers and metadata are a separate problem, best handled by a PDF tool's own redaction. And no rule set finds every name in free text, so read the result before you share it.