Anonymize sensitive data before sharing it
Sharing a text excerpt containing personal information can have serious privacy and GDPR compliance consequences. Fortunately, there are tools to automate this tedious task.
Why mask personal data?
GDPR compliance
Since May 2018, the General Data Protection Regulation (GDPR) requires minimizing the collection and transmission of personal data. Sharing a non-anonymized document can expose your organization to significant fines.
Real-world examples
- A developer shares a production log on Stack Overflow — it contains user email addresses.
- A support agent forwards a ticket to a vendor — it contains the customer's phone number.
- An accountant sends a sample CSV file — it contains real IBANs.
In all these cases, prior anonymization is mandatory.
What our tool can mask
Our data masking tool automatically detects and replaces:
| Data type | Original example | Masked result |
|---|---|---|
| john.doe@gmail.com | j.d@g.com | |
| Phone | +1 555 123 4567 | +1 555 * |
| IBAN | GB29 NWBK 6016 1331 9268 19 | GB |
| Card number | 4111 1111 1111 1111 | 4 * 1111 |
How to use data masking
- Go to webfiletools.com/en/masquer-donnees.
- Paste your text in the input area.
- Select the types of data to mask.
- Click Mask and retrieve the anonymized text.
- Copy or download the result.
Everything happens 100% in your browser — no text is sent to a server.
Best practices
Irreversible anonymization vs. pseudonymization
- Anonymization: masked data can no longer be linked to a person. Ideal for test datasets.
- Pseudonymization: replaced by a fictional but reversible identifier (with a key). Used to maintain internal traceability.
What the tool does not replace
The tool detects recognizable patterns. It cannot guess:
- Uncommon proper names
- Internal references (case numbers, client codes)
- Implicit context ("my neighbor in apartment 3B")
For full anonymization of sensitive documents, a manual review is still recommended.
Conclusion
Data anonymization is no longer optional — it is a legal obligation and a professional best practice. Our masking tool lets you process your texts quickly, locally and for free.