This paper reports on an auto-ethnographic study aiming to identify insights into the practice of using smartphone to facilitate online testing in context of second language teacher education (SLTE). In total of fifty-four pre-service teachers participated in the study. Two methods were employed to collect data, including observation and written-reflection. Additional data gathered from interview and students’ activity logs on the website were also used to triangulate the data collected through the initial methods. A thematic analysis were carried out to analyse the qualitative data. Findings of the study show that smartphone is viable as an electronic tool to facilitate online testing in SLTE context. More importantly, the use of Moodle as an online test platform fits both the teacher and the students’ needs on several aspects such as design, test structure, and online test activity. The study also highlights benefits and challenges of employing sequential and multiple attempt test modes and delayed feedback on online tests. Implications of the findings on the practice of online testing using smartphone in context of SLTE and further research in the field are also discussed.