Chemists have long been familiar with search engines that aspire to index a large proportion of the chemical literature. Think for example the old-generation (and commercial) SciFinder (Scholar) and Reaxys or those that arrived in the 1990s in the online era‡ such as the non-commercial Pubchem or ChemSpider (there are more). But you may not be as familiar with the latest generation of global search engines and here I will focus on three relatively new ones that specialise specifically in tracking down data rather than just publications.