This study was aimed to investigate the implementation of a web-based vocab game in improving students’ vocabulary achievement and to determine whether there was a significant difference in vocabulary achievement between students taught using the game and those taught through conventional learning activities. This study employed a quantitative quasi-experimental design involving 48 seventh-grade students at SMPN 1 Puding Besar, consisting of 24 students in the experimental class and 24 students in the control class. The data were collected through observation sheets, pre-test, post-test, and documentation. The pre-test and post-test data were analyzed using SPSS. The observation sheet results showed that the percentage of students demonstrating a very good understanding of noun vocabulary increased from 8% to 87%, while adjective vocabulary increased from 8% to 83%. The experimental class mean score increased from 56.87 in the pre-test to 75.62 in the post-test, while the control class mean score increased from 57.08 to 63.54. The Independent Samples T-Test showed that the absolute value of the t-obtained (2.282) was higher than the t-table (2.013), and the significance value was 0.027 < 0.05. Therefore, the null hypothesis was rejected. The findings indicate that the web-based vocabulary game effectively improved students’ vocabulary achievement and resulted in a statistically significant difference compared with conventional learning activities. These findings highlight the potential of web-based vocabulary games to support vocabulary learning among seventh-grade students.