The major objective of the research was to examine the utility of authentic assessment tools using the technology gadgets and their value in addition to the assessment of 21st-century skills under the umbrella of 21st century skills. These five domains: a) Critical and innovative thinking skills b) Interpersonal skills c) Intrapersonal skills d) Global Citizenship e) Media and Literacy Skills were assessed under the umbrella of 21st century skills. Secondly, to determine the acquaintance of subjects with the technology embedded assessment tools, ICT literacy level of students was also assessed. The study was developmental in nature; panel survey design was used to examine the utility of authentic assessment tools using technology gadgets and their value addition for the assessment of 21st century skills through different authentic assessment tools, over a period of two semesters. Through the period of intervention data were collected from a sample of postgraduate level students enrolled under the blended learning program at Allama Iqbal Open University, Islamabad. A total of 25 M.Phil. students experienced the intervention. A significant positive change was observed in the development of students' ability to draw conclusions (p= 0.004), decision making (p=0.013) and implementing new ideas (p=0.000) was observed in post-test under the investigation of critical and innovative thinking skills. Moreover, it was also found that the ability to be persistent showed significantly positive improvement in the post-test scores of learners in online learning management system (p=0.001). Global Citizenship values (p=0.037) was significantly improved among the learners after intervention (p<0.05).