Kemiripan judul skripsi merupakan masalah yang kerap muncul pada tahap awal penyusunan tugas akhir mahasiswa, berpotensi menurunkan kebaruan penelitian dan menyulitkan proses bimbingan. Penelitian ini merancang dan mengimplementasikan sistem pendeteksi kemiripan judul skripsi berbasis web menggunakan Cosine Similarity dengan pembobotan TF-IDF. Sistem diimplementasikan menggunakan PHP dan MySQL. Data judul dikumpulkan secara manual dari para peneliti/mahasiswa di berbagai fakultas Universitas Sembilanbelas November Kolaka. Evaluasi penerimaan pengguna dilakukan dengan model Technology Acceptance Model (TAM) yang dimodifikasi dengan konstruk Trust & Perceived Accuracy. Hasil pengujian pada 45 responden menunjukkan nilai rata-rata PU = 4,09; PEOU = 4,03; TPA = 3,79; ATU = 3,97; BI = 3,88 (kategori: Tinggi). Sistem mampu mendeteksi kemiripan judul dengan cepat dan memberikan keluaran skor kemiripan yang dapat membantu proses validasi akademik. Rekomendasi pengembangan meliputi integrasi pendekatan semantik dan mekanisme pembaruan basis data otomatis. Title similarity among undergraduate theses reduces novelty and complicates supervision and assessment processes in higher education. This research designs and implements a web-based title similarity detection system using Cosine Similarity with TF-IDF weighting. The system is implemented using standard PHP and MySQL as the database. Thesis title data were collected manually from researchers and students across faculties at Universitas Sembilanbelas November Kolaka. User acceptance was evaluated using the Technology Acceptance Model (TAM) augmented with a Trust & Perceived Accuracy construct. The system demonstrates fast processing and reliable similarity scoring; TAM results (N = 45) indicate high acceptance across constructs (PU = 4.09; PEOU = 4.03; TPA = 3.79; ATU = 3.97; BI = 3.88). The proposed solution can support academic administration by early detection of title duplication and guiding revision processes. Recommendations for future work include semantic similarity integration and automated indexing for continuous database growth.