Penelitian ini bertujuan menganalisis efektivitas penggunaan aplikasi D’Volleyball Metrics dalam pembelajaran bola voli di SMP Negeri 1 Indralaya. Metode yang digunakan adalah Penelitian Tindakan Kelas (PTK) melalui dua siklus tindakan dengan instrumen berupa tes kognitif dan observasi keaktifan belajar. Subjek penelitian terdiri atas 32 siswa kelas VIII. Hasil menunjukkan peningkatan signifikan pada setiap siklus. Pada pra-siklus, ketuntasan pengetahuan siswa hanya 21,88% dengan rata-rata 52,71, dan keaktifan belajar 47,27%. Siklus I meningkat menjadi 56,25% (pengetahuan) dan 69,73% (keaktifan). Pada siklus II, hasilnya melonjak menjadi 90,63% untuk pengetahuan dan 81,25% untuk keaktifan. Dengan demikian, penerapan aplikasi D’Volleyball Metrics terbukti efektif meningkatkan hasil belajar dan keaktifan siswa dalam pembelajaran bola voli. Disarankan pengembangan fitur audio-visual offline agar tetap optimal meski tanpa koneksi internet Abstract This study aims to analyze the effectiveness of using the D'Volleyball Metrics application in volleyball learning at SMP Negeri 1 Indralaya. The method used is Classroom Action Research (CAR) through two action cycles with instruments in the form of cognitive tests and observations of learning activity. The research subjects consisted of 32 eighth-grade students. The results showed a significant increase in each cycle. In the pre-cycle, student knowledge mastery was only 21.88% with an average of 52.71, and learning activity was 47.27%. Cycle I increased to 56.25% (knowledge) and 69.73% (activity). In cycle II, the results jumped to 90.63% for knowledge and 81.25% for activity. Thus, the application of D'Volleyball Metrics proved to be effective in improving student learning outcomes and activity in volleyball learning. It is recommended that offline audio-visual features be developed to remain optimal even without an internet connection. Translated with DeepL.com (free version).