Key Limes vs. Limes — What’s the Difference?

published Mar 5, 2022
We independently select these products—if you buy from one of our links, we may earn a commission. All prices were accurate at the time of publishing.
Post Image

The fresh and delightfully tart flavor of lime is almost instantly recognizable. There’s practically never a wrong time to make a rich key lime pie, and freshly squeezed lime juice is a perfect way to add brightness to all manner of dishes and drinks, including tacos, margaritas, and much more. But when a recipe calls for “Key limes” as opposed to just “limes,” what exactly does that mean?

Read more: Recipes That Make the Most of Limes

There are two main types of limes you’re likely to come across at the grocery store: the Persian lime and the Key lime. Persian limes, which are typically just labeled “limes” in U.S. grocery stores and in recipes, have origins in Persia, or present-day Iran. Key limes are native to Southeast Asia but get their name from the Florida Keys, where they were later harvested.  

What’s the Difference Between a Key Lime and a Persian Lime?

The most noticeable difference between a Key lime and a Persian lime is size. A Persian lime, the variety most available at local supermarkets, is medium in size, around 2 to 3 inches in diameter, and oblong. A Key lime, also known as a Mexican lime, West Indian lime, or Florida Key lime, is significantly smaller and rounder. Key limes also contains seeds, while the Persian limes — sometimes called a Tahitian limes — found in grocery stores typically do not. 

Do Persian Limes Taste Like Key Limes?

Not quite! Persian limes are more acidic than Key limes and thus often have a more tart flavor. Key limes, which are known for being particularly aromatic, are typically sweeter in taste, making them a perfect ingredient for the refreshing pie they’re most known for (or for these fun Key lime pie-inspired s’mores).

Can You Substitute Persian Limes for Key limes?

Yes! Depending on where you are, you might find that Persian limes are the only limes available. Persian limes are OK to use as a substitute in many lime dishes, like these cilantro-lime chicken quesadillas. If only the distinct flavor and aroma of Key limes will do but you can’t find them fresh, many stores carry bottled Key lime juice as well — you can also buy it online from sources like Amazon. Just be sure to check the label and make sure it’s 100% unsweetened Key lime juice before you add it to your pie.