In 2021, PubChem, a public chemical database, made significant improvements to its data content and web interfaces. Over the past two years, PubChem integrated data from more than 100 new sources, including chemical-literature links from Thieme Chemistry, chemical and physical property links from Springer-Materials, and patent links from WIPO. These updates enhanced the database's ability to provide users with faster access to information and improved data organization. PubChem also introduced new services such as the PubChem Periodic Table, Pathway pages, and Knowledge panels, which help users find relationships between chemicals, genes, and diseases. In response to the COVID-19 outbreak, PubChem created a special data collection containing information related to the virus and its impact on public health. The database now contains over 293 million substance descriptions, 111 million unique chemical structures, and 271 million bioactivity data points. PubChem's web interfaces were redesigned to be more user-friendly and mobile-friendly, with responsive design that works on both desktop and mobile devices. The new homepage allows users to search multiple data collections simultaneously and supports chemical structure queries. Knowledge panels were introduced to help users quickly identify important relationships between chemicals, genes, and diseases. PubChem also integrated data from several ToxNet databases, enhancing the FAIR (Findable, Accessible, Interoperable, Reusable) nature of chemical information. PubChem's data model was updated to support programmatic access, and new web services such as PUG-REST and PUG-View were introduced. The database also provides links to molecular property data from SpringerMaterials and to patent data from WIPO's PATENTSCOPE. PubChem's data are freely available to the public and can be accessed through web interfaces or programmatically via PUG-REST and PUG-View. The database continues to expand its data collection, ensuring that users have access to the most up-to-date and comprehensive chemical information.In 2021, PubChem, a public chemical database, made significant improvements to its data content and web interfaces. Over the past two years, PubChem integrated data from more than 100 new sources, including chemical-literature links from Thieme Chemistry, chemical and physical property links from Springer-Materials, and patent links from WIPO. These updates enhanced the database's ability to provide users with faster access to information and improved data organization. PubChem also introduced new services such as the PubChem Periodic Table, Pathway pages, and Knowledge panels, which help users find relationships between chemicals, genes, and diseases. In response to the COVID-19 outbreak, PubChem created a special data collection containing information related to the virus and its impact on public health. The database now contains over 293 million substance descriptions, 111 million unique chemical structures, and 271 million bioactivity data points. PubChem's web interfaces were redesigned to be more user-friendly and mobile-friendly, with responsive design that works on both desktop and mobile devices. The new homepage allows users to search multiple data collections simultaneously and supports chemical structure queries. Knowledge panels were introduced to help users quickly identify important relationships between chemicals, genes, and diseases. PubChem also integrated data from several ToxNet databases, enhancing the FAIR (Findable, Accessible, Interoperable, Reusable) nature of chemical information. PubChem's data model was updated to support programmatic access, and new web services such as PUG-REST and PUG-View were introduced. The database also provides links to molecular property data from SpringerMaterials and to patent data from WIPO's PATENTSCOPE. PubChem's data are freely available to the public and can be accessed through web interfaces or programmatically via PUG-REST and PUG-View. The database continues to expand its data collection, ensuring that users have access to the most up-to-date and comprehensive chemical information.