Many kinds of tinned fish are available to every shopper, but the two primarily popular are anchovies and sardines. Despite being oily and small, these tinned fish have distinct tastes, looks, origins, and flavors. Sardines are native to the southern Mediterranean sea. They are larger than anchovies and are in the same family as herring, while anchovies are oiler and more minor.
What are sardines: Sardines, which can also know as pilchards, are in the herring family Clupeidae. The word sardines was used in the 15th century. In length, they range from 15 to 30 cm (6 to 12 inches).
What are Anchovies: Anchovies are tiny, green-colored fishes with blue reflections in water, caused by a silver-colored long stripe that runs from the base of their caudal fin. Anchovies are in the family of Engraulidae. They pack a potent punch, one that is also salty. The range in length is from 2 to 40 cm (1 to 151/2 inches).
Sardines Vs. Anchovies:  Here are some differences between Sardines and anchovies.
Look different: Sardines are bigger and can be up to 20 cm long. Sardines are white flesh fishes and are usually identified by their slightly protruding lower jaw. On the other hand, anchovies are sold darker and often less than 15 cm in length.
Different Taste: Sardines are fishy tasting but slightly less intense than anchovies. Anchovies are known for their distinct umami-rich and powerfully flavored due to the curing process.
Used differently: Anchovies pack a solid and salty punch, so they are an excellent addition to pizza and other tasty dishes that require some intense flavor. Sardines complement dishes that need a less intense flavor. Sardines and anchovies can be prepared through filleting, frying, grilling, or other fish cooking methods.
Can you substitute one for the other?
It is not a fine idea to substitute anchovies for sardines or oppositely. These two fish act very differently when cooked. Anchovies tend to melt away, and they flavor the whole dish with their savory saltiness. On the other hand, sardines are meatier and more mellow in taste. The thick flesh of sardines won't dissolve freely the way an anchovy fillet. It will only cook more. Changing sardines into a Caesar salad dressing somewhat of anchovy would be nothing small of catastrophic.
Sardines and anchovy's health benefits: Both fishes provide the same nutrients and the same benefits. Anchovies are healthier than sardines due to their wealthy percentage of heart-healthy omega-3 fatty acids, B vitamins, protein, and minerals. Sardines contain more cholesterol and fat than anchovies. Anchovies provide riboflavin, B6, B5, iron, folate, zinc, zinc, selenium, and potassium.
Are sardines and anchovies good for you?
Eating 2 to 3 grams provides even more benefits to heart health, according to UMHS. Sardines and anchovies contain rich amounts of these beneficial fats compared to other fish spices. Anchovies canned in oil contain 2 grams of omega-3s, while sardines have almost 1.6 grams of omega-3s

Sardines vs. Anchovies