Holidaymakers typically rely on experienced tour guides and local companies to recommend excursions to medieval castles and spectacular waterfalls, but the world's biggest tour operator has said it will entrust the service to artificial intelligence instead. The German travel company Tui has started using ChatGPT in its app to provide holiday recommendations, in the latest sign of traditional businesses racing to harness AI. ChatGPT was released in November by the startup OpenAI, and became the fastest-growing consumer app ever as users flocked to try it out. The rapidly improving technology can produce comprehensible language and even photos and videos by crunching through and synthesising huge amounts of data. Tui's feature has been released to half of UK app users, with the aim of introducing it to all "in the next weeks", a spokesperson said.