Is WA Number Checker - Check & Verify WA Number safe?

Checks bulk phone-number lists to identify which numbers are active on WhatsApp.

This extension runs on WhatsApp Web after you log in and lets you create checking tasks for entered numbers, generated ranges, or CSV imports. It saves checking progress to history and lets you download success and failure results as CSV files. The store description states that processing happens on the local computer and that data is not shared with third parties.