A BUDGET traveler put on their thinking caps after comparing two airlines' carry-on testers. Even though the testers were reportedly the same size, her luggage only managed to fit into one. TikToker WanderingsWhimsy shared the airline investigation in a viral video.

The video, which has garnered over five million views, exposed the size discrepancy between Frontier and Spirit Airlines' carry-on testers. The TikToker held up a red bag, which she revealed to to be the Baboon to the Moon Go Bag Mini. "It's pretty full, but not packed out," she said.

Lifting the bright red carry-on, she was able to easily slot it into the Spirit Airlines tester. Right next to it, however, was the Frontier Airlines tester, which was considerably smaller in comparison. After much pushing and shoving, she was barely managed to squeeze the red bag into the slot.

"Spirit vs. Frontier sizer comparison. Both are listed as 18x14x8.

Somebody is lying," she wrote. Experienced travelers came out with similar experiences at the airport. "I swear I've always flown Frontier, used the same bag for five years and the last year my bag doesn't fit anymore," said one commenter.

"Frontier is everything they say about Spirit times 20," said another. "Mine fit in the bag checker when I walked into the airport and magically it didn’t at the gate with nothing even being opened." said a third.

One woman explained that she was sure she had the right size luggage but was shocked when she was forced to pay. "I had a carry.