Hopefuls trying their luck will perform in front of producers and if they impress they'll sing for the judges later in the competition.
Returning host Dermot O'Leary who is in Cardiff for the auditions, said: "As always I'm looking forward to the laughs, the hugs, maybe not so much the tears, and watching really talented people... and some not-so-talented people.
"But that's the beauty of the show - you never know who's up next."
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Fine and sunny tomorrow morning with lots of sunshine to start the day. Feeling colder though, with maximum temperatures of 13°C.
Kathryn Tresilian reports from the town where the body of a 47-year-old woman was found dismembered in Pontypridd on Friday.
Some bright spells this afternoon, with outbreaks of rain. Top temperature 15°C.