Social media has become deeply integrated into students’ daily lives, extending beyond social use into informal academic practices, including self-assessment. This study examines how EFL students at a university use social media to assess their own academic abilities, the extent to which they engage in academic social comparison through these platforms, and the difficulties they encounter in doing so. A mixed-methods approach was employed, using an online questionnaire comprising closed and open-ended questions administered to 133 students. Quantitative findings revealed that the majority of students used social media for academic self-assessment on a frequent basis, with YouTube and WhatsApp emerging as the most commonly used platforms. While social comparison was a common practice among students, it was not strongly associated with increased motivation or academic confidence. Qualitative findings further revealed that students primarily used social media for comprehension checks, language practice, and peer feedback, while also reporting challenges related to distraction, unreliable information, and negative social comparison. These findings suggest that social media functions as an informal, self-directed space for academic self-assessment, one that offers meaningful opportunities for reflection and feedback but also carries risks that may undermine effective learning if left unaddressed. The study is limited by its focus on EFL students at a single university and its reliance on self-reported data, and future research should extend to larger, more diverse samples across multiple institutions and disciplines. The findings nonetheless highlight the need for greater digital literacy support and suggest that educators consider ways to intentionally integrate informal social media practices into formal academic guidance.