Which non-alcoholic mixer is commonly used in cocktails?

Tonic water is a non-alcoholic mixer that is commonly used in cocktails, particularly in drinks like a gin and tonic. Its unique flavor profile, which combines a slight bitterness due to quinine with a hint of sweetness, complements the spirit it is mixed with, enhancing the overall taste experience of the cocktail. Tonic water is also carbonated, adding a refreshing fizz that makes it popular among both casual drinkers and cocktail enthusiasts.

The other mixers listed, while popular in their own right, are more often categorized with specific drinks rather than as foundational cocktail mixers in the way tonic water is. Ginger ale, for example, is frequently used in mixed drinks, but it does not have the same level of association with particular spirit pairings as tonic. Orange juice and cranberry juice are both common in cocktails, but they tend to create drinks with specific flavors that may not align as universally with a wider variety of spirits compared to tonic water.