The article introduces circBase, a database and website designed to facilitate research on circular RNAs (circRNAs). CircRNAs are single-stranded RNA molecules that form a "head-to-tail" splice junction, often produced from exons. Despite their unknown biological functions, circRNAs exhibit high stability and specific spatiotemporal expression patterns, making them potential biomarkers and valuable for further research. The authors developed circBase to provide a centralized resource for circRNA data, including merged and unified datasets, evidence supporting their expression, and genomic context. The database offers scripts to identify known and novel circRNAs in sequencing data and supports flexible queries, data export, and integration with external resources like the UCSC Genome Browser and doRiNA. The database is freely accessible at http://www.circbase.org/ and aims to serve the community by pooling and making accessible published data sets from different laboratories.The article introduces circBase, a database and website designed to facilitate research on circular RNAs (circRNAs). CircRNAs are single-stranded RNA molecules that form a "head-to-tail" splice junction, often produced from exons. Despite their unknown biological functions, circRNAs exhibit high stability and specific spatiotemporal expression patterns, making them potential biomarkers and valuable for further research. The authors developed circBase to provide a centralized resource for circRNA data, including merged and unified datasets, evidence supporting their expression, and genomic context. The database offers scripts to identify known and novel circRNAs in sequencing data and supports flexible queries, data export, and integration with external resources like the UCSC Genome Browser and doRiNA. The database is freely accessible at http://www.circbase.org/ and aims to serve the community by pooling and making accessible published data sets from different laboratories.