There are many ways to elevate a classic tartar sauce, but it's worth considering an alternative condiment if you want to make a better-fried fish sandwich.
Aioli or remoulade sauce make great switches to replace tartar sauce. The two sauces are traditional partners for seafood and shellfish and pair well with fried foods.
Aioli consists of garlic and oil, but you'll likely see a creamier mayo-like variation made with egg yolks. With some lemon, aioli provides the freshness a fried sandwich needs.
Remoulade is highly customizable, so you can adapt it to your tastes and the individual ingredients of your fish sandwich.
So many variations exist for the two classic sauces that you will find the perfect match for a next-level fish sandwich, no matter your style.