The only safe software methods require paid credits (e.g., NetUnlock, DoctorSIM, MobileUnlocked). They cost $15–$30, not free.

Do not enter the wrong code more than 5 times. Most Samsung phones have a fail-safe that permanently locks the SIM card or requires a factory reset after too many failed attempts.

If you cannot find a free code via a generator, how can you unlock your phone for $0? You use official carrier channels. These methods are 100% legal, safe, and effective.