There is no one-size-fits-all answer to this question, as the effectiveness of bleach and vinegar at killing mold will vary depending on the type of mold, the severity of the mold problem, and the specific condition of the surface or area where the mold problem is occurring.
However, in general, bleach is generally more effective than vinegar at killing mold because it has a higher pH level and can penetrate deep into porous surfaces. Bleach also has a residual effect that can keep mold from growing back after it is killed.