Blair or Serena Hair
Credit: Sipa; Startraks; Time Inc Digital Studio

With Gossip Girl’s 100th episode airing tonight, we want to know once and for all: Are you a Blair or a Serena? Try on their hairstyles in our Hollywood Makeover Tool to find out! Just upload your photo to see yourself in Serena van der Woodsen’scarefree blonde waves orBlair Waldorf’s flawless pin-straight strands. Then, share your makeover on Facebook and Twitter to see what all of your friends think of your Upper East Side-inspired ‘do. Head over to ourHollywood Makeover Toolto try on their hairstyles now, and tune in to the CW tonight at 8/7c to catch the new episode.

Plus, see the top GG fashion moments!