BACKGROUND: Autologous fat transplantation has been a cornerstone of tissue regeneration for decades. However, there is no standardized selection system or criteria for fat graft selection, often relying heavily on the surgeon's experience. OBJECTIVES: This study aimed to investigate various types of fat derivatives, both in vitro and in vivo at the same condition. METHODS: We collected traditional fat granules of different sizes and SVF-gel, evaluating the viability of ADSCs isolated from them and their performance after grafting into mice. RESULTS: Large fat granules exhibited more complete adipocyte structures, and the isolated ADSCs demonstrated superior differentiation, proliferation, and secretion capacities. They also showed excellent volume retention after 12 weeks. In contrast, ADSCs isolated from SVF-gel displayed lower vitality. However, grafts from SVF-gel exhibited the highest volume maintenance rate among the four groups after 12 weeks, closely resembling normal adipose tissue and displaying significant vascularization. Compared to large fat granule and SVF-gel group, medium and small fat granule grafts exhibited lower volume retention and less angiogenesis. CONCLUSIONS: Through preclinical studies, the flexible clinical use of different fat grafts can be tailored to their unique characteristics. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .