One of the best things about eggs, in addition to how nutritious they are, is how versatile they are - and how many functions they perform in any recipe they're used in.
The Function of Eggs in Recipes
Eggs add moisture to cakes and muffins. When heated, they act as a binder in meatloaf and meatballs. The whites act as a leavener and provide the lift in souffles and the structure to meringues.
And the yolks add flavor and richness to any recipe they're used in while the protein helps with structure. Eggs also help baked goods to brown.
In fact, in many recipes, eggs provide several of these important functions. So that makes finding a truly worthy substitute for an egg sort of difficult.
But with the current scarcity of eggs and the rising prices, I know lots of people are looking for other ingredients they can use in their cooking and baking to replace the eggs. So here goes.
Although nothing is going to make a perfect omelet like an egg, or replace a perfectly cooked soft-boiled or jammy egg, and nothing is going to fry up like an egg, it is possible to mimic the performance of eggs in certain instances with these substitutes.
The 12+ Best Substitutes for Eggs that (Sort of) Work
1. Aquafaba
Aquafaba, otherwise known as the liquid in a can of chick peas, is probably the easiest substitute for an egg that you can use.
Simply strain the liquid from the can and then measure out 2 tablespoons for each egg white your recipe calls for (or use 3 tablespoons if you need to substitute the whole egg).
Aquafaba can also be whipped similar to egg whites for meringues or souffles. Although I personally have never tried making a pavlova with aquafaba, master baker Zoe Francois has a recipe for vegan meringues here that she swears by.
I find the smell (and taste) of the chickpea liquid kind of off-putting, so I would hesitate before using aquafaba in my baked goods. In hummus, yes absolutely; in a cake, I'm not so sure about. But never fear, there are other options!
2. Carbonated Water, Soda Water or Seltzer
If it's lift you're looking for, you can add 1/4 cup of carbonated water for each egg white your recipe calls for. The bubbles and effervescence will help your baked goods rise. This is the substitution that The Kitchn prefers. 
3. Vinegar + Baking Soda
Substituting 1 tablespoon of vinegar and 1 teaspoon of baking soda for the egg whites in your recipe can also help add some air to your recipe.
If what you're looking for is a binder and additional moisture in your recipe to replace the egg, there are also a couple of things you can try.
For Savory Dishes
1. Mashed Avocado
1/4 cup of mashed avocado can replace the egg in savory dishes. It will add moisture, binder and fat as well as subtle flavor. You can also use mashed avocado in sweet recipes as well due to it's fairly innocuous flavor.
2. Mashed Potato
You can also sub in 1/4 cup of mashed potato in meatloaf, for example, to add moisture and a binder.
3. Pumpkin Puree
Pumpkin puree will work in the same way, with 1/4 cup adding moisture and a binder to your savory recipes and replacing an egg.
For Sweet Dishes
1. Applesauce
1/4 cup of applesauce can stand in for the egg in sweet recipes. Just remember, you'll be adding some apple flavor, as well as sweetness, especially if you don't use unsweetened applesauce, so you might need to adjust the amount of sugar in the recipe accordingly.
2. Mashed Banana
Mashed, ripe banana can stand in for eggs as well. But again, remember that bananas are pretty sweet, and will lend a distinct flavor to your baked goods, so substitute the bananas wisely. 1/4 cup of mashed banana equals one egg.
Either Sweet or Savory Dishes
The following egg substitutes should work in either sweet or savory recipes, but remember they are only going to add moisture and a binder. If you need your baked goods to rise, you might want to use this substitution instead:
1 1/2 tablespoons neutral oil
+ 1 1/2 tablespoons water
+ 1 teaspoon baking powder
1. Plain Yogurt or Sour Cream
2. Buttermilk
3. Neutral Oil
3. Flax Seed + Water
4. Chia Seeds + Water
In Summary
Bottom line, there is no perfect substitute for eggs, which is part of what makes them so unique and fascinating. They perform so many functions in recipes.
You might need to do some trial and error to see what works best for you, and remember that many of these substitutions are going to add flavors that might not mesh with every recipe.
But to be completely honest instead of looking for substitutes, try to stretch the eggs you do buy as far as you can.
- Freeze extra eggs (or yolks and whites) so nothing goes to waste
- Have a few dessert recipes that don't require eggs like shortbread or scones.
- Use milk washes instead of egg washes on your pie crusts, or dredge cutlets in buttermilk instead of whisked egg before you bread them.
Then you can save your eggs to use in the recipes where they really matter.
Or, just get some chickens.
