OpenRouter Free Models - PII Masking

Tests whether free LLMs can accurately detect and mask Personally Identifiable Information in text, limited to four entity types: first name, last
name, email address, and IPv4 address.

Example:

Input: "Contact john.doe@example.com or reach out to John Doe at 192.168.1.1"
Output: "Contact [EMAIL] or reach out to [FIRSTNAME] [LASTNAME] at [IPV4]"

A practical privacy-focused benchmark — models must identify sensitive entities precisely without over-masking surrounding context.