Developers can use GET /users/@me for their own info, but there’s without an OAuth2 token and user lookup permissions. Bulk checking is explicitly forbidden.
But again, running unknown code is never fully safe. discordusernamecheckermainrar work
If you just downloaded this file and aren't sure if it's safe: yet. Developers can use GET /users/@me for their own
: Beyond Discord, these programs can steal browser cookies, saved passwords, and even credit card information stored on your device. How to Safely Check Username Availability these programs can steal browser cookies