How To Tell The Difference Between Full House Twins Mary-Kate And Ashley Olsen

Mary-Kate and Ashley Olsen may have come a long way since their days on "Full House," but they will always be known as little Michelle Tanner in our hearts. The twins started on the show at just nine months old back in 1987 (via IMDb). It was said that the babies landed the role because they were the only pair of twins that did not cry during the audition process, per E! News. After landing the part, they continued to grow up on our screens, switching off playing the role of the youngest Tanner sister for eight seasons (via Insider).

While the two rarely appeared together on screen — they acted together just four times throughout all eight seasons — fans were constantly wondering which twin was in each episode. And while the Olsens are not identical twins but rather fraternal, according to E! News, their similarities are immense, and telling them apart can be quite tricky. But if you really want to know who you are watching while binging reruns of "Full House," here is how to tell the difference between them.

While they mainly played the role of Michelle separately, the Olsen twins were hard to differentiate even when standing next to each other. The twins do have some key differences, although they are hard to notice, especially on a television screen. In fact, the differences are so small, it comes down to a freckle. While Mary-Kate and Ashley told Oprah in 2004 that it has since disappeared, a key difference was the freckle above Ashley's lip. The twins also explained that Ashley is one inch taller than Mary-Kate.

But, possibly the biggest difference between the two is their dominant hand. Ashley is right-handed and Mary-Kate is left-handed. While this is an easy way to tell the two apart, it was unlikely to see them in a scene using a pen or flexing their dominant hand.

While it's nearly impossible to tell the girls apart during their time on "Full House," as they got older, they began to look a bit different. By the early 2000s, the girls had become women and a few key differences separated their once identical faces. Life and Style Mag reports that around 2002, Ashley's fuller lips became apparent and by 2003, the girls made it easy on fans when Mary-Kate dyed her hair red and then brown, while Ashley kept hers their signature blonde.

While Mary-Kate has since returned to her blonde roots, the pair, who are now in their mid-30s, remain largely out of the spotlight, making it hard to not only tell them apart but to see them at all. Per We Got This Covered, they prefer to keep their lives private despite their fame. In fact, they don't even have social media, a rarity among people their age. Still, the twins continue to work together on their fashion line and have helped shape their sister Elizabeth's acting career.