Rfam 12.0 is an updated version of the RNA families database, featuring improvements in RNA homology detection and annotation. The database now includes 2450 families, with 260 new additions, including the large subunit ribosomal RNA family. The Rfam database uses Infernal 1.1 for homology detection, which is significantly faster and more sensitive than previous versions. This upgrade allows for more accurate identification of RNA homologues in genomic and metagenomic data. The new pipeline also enables users to annotate RNAs in their own datasets with their own computing resources. Rfam 12.0 includes new features such as the inclusion of short sequence- and structure-based RNA motifs, and the addition of RMfam motifs to seed alignments and secondary structure graphics. The database also provides improved data visualization and annotation tools, including clan competing to reduce annotation duplication. Rfam 12.0 also includes new family-specific annotations and cross-references to other resources. The database has been moved to the European Bioinformatics Institute, and the production pipeline has been streamlined and parallelized. Rfam 12.0 also includes improved handling of truncated RNA sequences and allows for more accurate annotation of RNA families. The database now includes annotations for Rfam families of the type Gene to RNA Central and cross-links from RNA Central to Rfam. Rfam continues to rely on community contributions, including through Wikipedia, annotations provided through the helpdesk, and new entry submissions. The database is now more accessible and user-friendly, with improved data displays and annotations. Rfam 12.0 is a significant update to the RNA families database, providing improved homology detection, annotation, and data visualization tools for RNA researchers.Rfam 12.0 is an updated version of the RNA families database, featuring improvements in RNA homology detection and annotation. The database now includes 2450 families, with 260 new additions, including the large subunit ribosomal RNA family. The Rfam database uses Infernal 1.1 for homology detection, which is significantly faster and more sensitive than previous versions. This upgrade allows for more accurate identification of RNA homologues in genomic and metagenomic data. The new pipeline also enables users to annotate RNAs in their own datasets with their own computing resources. Rfam 12.0 includes new features such as the inclusion of short sequence- and structure-based RNA motifs, and the addition of RMfam motifs to seed alignments and secondary structure graphics. The database also provides improved data visualization and annotation tools, including clan competing to reduce annotation duplication. Rfam 12.0 also includes new family-specific annotations and cross-references to other resources. The database has been moved to the European Bioinformatics Institute, and the production pipeline has been streamlined and parallelized. Rfam 12.0 also includes improved handling of truncated RNA sequences and allows for more accurate annotation of RNA families. The database now includes annotations for Rfam families of the type Gene to RNA Central and cross-links from RNA Central to Rfam. Rfam continues to rely on community contributions, including through Wikipedia, annotations provided through the helpdesk, and new entry submissions. The database is now more accessible and user-friendly, with improved data displays and annotations. Rfam 12.0 is a significant update to the RNA families database, providing improved homology detection, annotation, and data visualization tools for RNA researchers.