Hey J-14ers! We're taking a break for the holidays and wanted to leave you with a special treat: our most popular features of the year! Stay tuned! We'll be revealing more of your favorite posts throughout the holidays.

Can you believe that Ariana Grande is 21 years old today?! The birthday girl has gone through a major transformation these past few years, looking nearly unrecognizable in her early photos. We almost can't believe she's the same girl who started on Broadway then dyed her hair bright red for Victorious — she's grown up so fast! Tear.

Click through to see 21 throwback pics of Ariana looking way different, then let us know which pics made your jaw drop in the comments below. Don't forget to wish her a happy birthday, too!