Motivation: High throughput bisulfite sequencing (BS-seq) is an important technology to generate single-base DNA methylomes in both plants and animals. In order to accelerate the data analysis of BS-seq data, toolkits for visualization are required. Results: ViewBS, an open-source toolkit, can extract and visualize the DNA methylome data easily and with flexibility. By using Tabix, ViewBS can visualize BS-seq for large datasets quickly. ViewBS can generate publication-quality figures, such as meta-plots, heat maps and violin-boxplots, which can help users to answer biological questions. We illustrate its application using BS-seq data from Arabidopsis thaliana. Availability: ViewBS is freely available at: https://github.com/xie186/ViewBS. Contact: [email protected]. Supplementary information: Supplementary data are available at Bioinformatics online.