Taylor Swift performed at the 2013 Billboard Music Awards in an overly casual outfit.

She hit the stage to perform “22” while wearing a T-shirt that referenced another single, “Shake It Off.”

While the “Haters Gonna Hate” nod was fun, the overall design — a bright-blue T-shirt emblazoned with a white unicorn and rainbow text bubble — was a little silly.

In 2015, she donned a sparkling jumpsuit that matched her “1989” aesthetic.

Designed by Balmain, the all-white piece had two waist cutouts, all-over sparkles, and thin halter straps that extended into its V-shaped neckline.

The jumpsuit was a bit simple, and Swift’s smokey eye makeup and messy bob overpowered the look.

Swift amped up the drama on the 2013 red carpet.

Zuhair Murad created Swift’s minidress, which had long sleeves, a mesh back, and intricate beadwork from top to bottom.

The dress itself leaned a bit prom-ish, but Swift’s standout makeup, updo hairstyle, and glittering accessories made it more glamorous.

It’s no surprise that Swift wore a red gown at the event during her “Red” era.

Her Elie Saab dress was a bit bold for Swift at the time. It was sleeveless with a nude-illusion bodice, a lace overlay up top, and a floor-length skirt with long pleats.

Swift wore it with a pin-straight hairstyle — her signature at the time — and no jewelry. The look was dramatic, but it worked.

We started to see the evolution of Swift’s bodysuits at the 2019 awards show.

To perform “Me!” with Brendon Urie, Swift wore a single-shoulder bodysuit that was custom-made for her by Jessica Jones and Joseph Cassell, her personal tour costume designer and stylist.

The piece had pink, blue, and gold sequins across its bodice and sleeve, and matching fringe that created a miniskirt at the bottom.

Not only was the outfit fun, but it also perfectly represented her “Lover” era.

Her first appearance at the Billboard Music Awards in 2011 was one of her most glamorous.

Once again wearing Elie Saab, Swift sported a strapless, floor-length gown in a tan shade. It was covered from top to bottom in pink sequins, and her side-swept curls completed the look.

The ensemble looked glamorous but still youthful, and Swift’s minimal accessories proved that it was styled to perfection.

Swift’s goddess-style gown made for a memorable fashion moment in 2018.

Custom-made for Swift by Versace, the dusty-pink gown had asymmetrical sleeves, a form-fitting bodice, a thigh-high slit in its skirt, and a cape-style piece that extended down her back.

And that’s not to mention the textured details, from pink feathers along its neckline to silver, sparkling lace across the waist.

The powerful outfit is one of the most iconic looks Swift has worn on the Billboard red carpet.

Swift’s best Billboard Music Awards outfit came in 2019.

Raisa and Vanessa were the creative minds behind Swift’s ruffled, lilac minidress — arguably her best Billboard Music Awards look to date.

Its high, ruffled collar was something different for the musician, and its sheer sleeves and bodice added a slightly daring touch to the look.