It sounds like you're referring to — a classic Firefox add-on for manual web penetration testing, often used to craft and send custom HTTP requests, test for SQLi, XSS, and other vulnerabilities. The phrase "hackbarv29xpi better" suggests you're looking for a better or improved alternative to that older XPI (Firefox extension) version.
: Injecting varied cross-site scripting payloads with one click. hackbarv29xpi better
to capture the requests you craft in HackBar and perform advanced fuzzing. ⚠️ Security Warning Be cautious when downloading HackBar v2