Of course you can often find short bios by entering an artist’s name in a search engine and these can work fine if you examine them carefully. In general, the biographies posted by major museums, art galleries, and artists themselves, are of a higher quality than those provided by the many commercial sites such as Artcyclopedia, AskArt, Artnet, etc. Accuracy varies. Web bios for historic figures are frequently copied from public domain (pre-1923) sources. Wikipedia entries also vary, so check the “Talk” tab where the quality of the article may be discussed.
Curators, Educators, Gallerists, Critics, etc.
The most recent volumes of these are not covered in indexes and must be checked separately: