Antibodies have become a major class of medicines, with over 60 therapeutic antibodies currently approved for clinical use. Immunoglobulin G (IgG) contains N-linked glycans in its Fc domain, which play a crucial role in functions such as antibody-dependent cellular cytotoxicity (ADCC) and pharmacokinetics. Profiling N-linked glycans is essential for antibody drug development, quality control, and biosimilar production. However, glycan structures are highly heterogeneous due to complex biosynthetic pathways, leading to batch-to-batch variations that impact antibody efficacy and safety. Recent advancements in mass spectrometry and chromatography have enabled more precise structural analysis of N-linked glycans, improving functional predictions. To enhance IgG functionality, producing homogeneous glycoforms is a key step. This review discusses glycan remodeling technologies and their applications in optimizing IgG function.