Unlike your typical lime, a key lime is usually on the smaller side and tends to be more yellow in color. In comparison, key limes are less acidic but still produce a flavorful and aromatic juice, which makes them perfect for baking. Key limes also have thinner skins and more seeds than other limes.u003cbr/u003eu003cbr/u003eRegular limes can be used in place of key limes, but the end result will be a bit less sweet and a bit more sour.