The UniProt Knowledgebase (UniProtKB) aims to provide a comprehensive, high-quality, and freely accessible set of protein sequences annotated with functional information. In 2023, UniProtKB has over 227 million sequences and is working towards including a reference proteome for each taxonomic group. The database continues to extract detailed annotations from the literature to update or create reviewed entries, while unreviewed entries are supplemented with annotations from automated systems using machine-learning techniques. The scientific community also contributes publications and annotations to UniProt entries. The new UniProt website enhances user experience and makes data easily accessible, featuring access to AlphaFold structures for over 85% of entries and improved visualizations for subcellular localization of proteins. The database integrates data from various resources, including the ChEBI chemical ontology for small molecule annotations, and collaborates with external organizations to improve protein nomenclature and subcellular localization descriptions. UniProtKB remains a central hub of information, integrating data from multiple sources and providing robust tools for data exploration and analysis.The UniProt Knowledgebase (UniProtKB) aims to provide a comprehensive, high-quality, and freely accessible set of protein sequences annotated with functional information. In 2023, UniProtKB has over 227 million sequences and is working towards including a reference proteome for each taxonomic group. The database continues to extract detailed annotations from the literature to update or create reviewed entries, while unreviewed entries are supplemented with annotations from automated systems using machine-learning techniques. The scientific community also contributes publications and annotations to UniProt entries. The new UniProt website enhances user experience and makes data easily accessible, featuring access to AlphaFold structures for over 85% of entries and improved visualizations for subcellular localization of proteins. The database integrates data from various resources, including the ChEBI chemical ontology for small molecule annotations, and collaborates with external organizations to improve protein nomenclature and subcellular localization descriptions. UniProtKB remains a central hub of information, integrating data from multiple sources and providing robust tools for data exploration and analysis.