Credibility is a key factor in using textile sustainability labels as guidance and quality instruments. This article examines the credibility of various textile sustainability labels based on established requirements, highlighting the need for thematic and formal optimization. The study analyses 26 labels using a theoretical approach and evaluation matrix. Criteria for credibility include the coverage of environmental and social aspects, transparency of certification, consideration of the product lifecycle and independent third-party audits. Results show that 42% of the examined labels are rated as good, 27% satisfactory, 23% insufficient, and 8% inadequate. None achieved the highest category “demanding”. The analysis reveals that 77% of the labels cover both environmental and social themes, with water consumption, chemical limits, and wastewater management being the most frequently addressed environmental criteria. Social criteria often align with ILO core principles, focusing on fair wages, non-discrimination, and freedom of association. The study identifies improvements needed in transparency and thematic coverage. To enhance credibility, labels should provide clear and relevant descriptions, make criteria and audits publicly accessible, involve interdisciplinary stakeholders, undergo third-party certification, and consider the entire product lifecycle. The Findings suggest that optimizing credibility and transparency of textile sustainability labels can positively influence consumer decisions. Future research should focus on the specific impacts of individual criteria on label credibility and explore standardized reporting.