Overview of the ViralPrimer project. (A) The efficiency of PCR tests is affected by the variability in viral genome. Mutations near the 3ʹ end of the primer target region (designated as high-risk) can lead to false-negative results, highlighting the significance of continuous primer assessment. (B) Our project uses data from a mutation database incorporating the analysis results of various public sample sets (GISAID, COVID-19 Data Portal), enabling the assessment of mutations and samples concerning primer binding sites. Classification relies on the genomic location, length, and co-occurrence of mutations in each primer target region. The main features of the server are the options of searching in the genome, browsing primers, and primer mapping. The ViralPrimer webserver offers visualization tools, such as region viewers and mutation statistics, to aid in obtaining results and selecting optimal primers for specific regions. This tool further addresses the ongoing need for rapid primer testing and ensures the accuracy of diagnostic results.