This is everything: dry, wet, kitten through senior, ordinary everyday food and prescription diets. Around a quarter of what's here is veterinary food for diagnosed conditions, so the filters are worth using before you scroll.
Cats are not small dogs
This matters more than any brand comparison. Cats are obligate carnivores and need things they cannot make for themselves, taurine in particular, along with vitamin A and arachidonic acid in forms only animal tissue provides. Dogs make their own taurine. Cats don't.
A cat fed dog food for a long stretch can develop heart disease and sight problems from taurine deficiency. It's not a marketing distinction. If you have both animals and one keeps raiding the other's bowl, the cat eating dog food is the direction that matters.
Start with lifestage
Kittens need kitten food, and it isn't upselling: growing cats need more protein, more calories and more of several minerals than adults. Senior recipes usually adjust phosphorus and protein quality for older kidneys.
After that, think about how your cat actually lives. Most cats in this country are neutered and mainly indoors, and both lower daily calorie needs considerably. Sterilised and indoor recipes exist for that reason and are the mainstream choice, not a niche one.
Wet, dry or both
Both, if you can manage it. Cats have a weak thirst drive and take most of their water from food, so wet food does hydration work a water bowl often doesn't. Dry food is cheaper, keeps better once opened and suits grazing.
Plenty of cats live long healthy lives on dry alone. But if your cat has any history of urinary or kidney trouble, or is getting on, wet food alongside is worth the extra. If you feed both, count both towards the daily total rather than adding one on top of the other.
Complete or complementary
Check the pack, particularly with wet food. Complete means it's a full diet on its own. Complementary means it's a topper and isn't balanced by itself. Both are here and both are fine products, but a cat fed only complementary pouches for months can genuinely run short of something.
Prescription diets
The veterinary food here works by restricting or adjusting things a healthy cat needs, which is why it isn't a general upgrade and some of it is actively unsuitable for a well cat. If your vet named a diet, buy that exact product. If they didn't, start with an appointment rather than a bag of food.
When not to change food
If your cat is well, holding weight, with a decent coat and using the tray normally, the food is working. Switching for its own sake usually buys you a fortnight of upset stomach and a cat sulking at the bowl.
And when you do change, mix it in over a week or two. One thing worth knowing: never try to wait a cat out. A cat that stops eating for more than a day or two can develop serious liver problems, and quickly. If yours refuses food and won't be tempted, ring your vet rather than holding firm.