Do kittens need food available at all times?

I adopted two kittens a little over a month ago at 10 weeks, they are now around 16 weeks and are currently eating 4health Grain Free Whitefish, Pea & Potato with Real Turkey Recipe available all day in a bowl, which I refill once a day, as well as a 5.5 ounce can of either friskies, 4 health, daves, or other brands split in the morning and evening. I'd like to know if these guys need food accessible all day, I know free feeding most animals is not recommended, so I wanna make sure they are not getting too much. I don't like the idea of feeding any dry food, and I planned on feeding solely wet food once they are older, but for now since theyre eating so much, I am using the dry food too.

Free feeding is one of those never ending debates and depends on your situation (in my opinion). On one side there are people who say that cats can and will self-regulate their diet to maintain a good weight. One the other side there are those who say that cats will overeat if given the opportunity. 

What is the truth? Which is best? There really isn't one. 

From my own personal experiences and cats, it really depends on the cats themselves. I have had cats who are perfect self regulators and stay perfect weight and I've had over-eaters too whom I have had to limit their intake. Honestly, it is which ever works best for you and your cats. In general, I think that if you raise a kitten/cat as a free feeder they will regulate better. As long as they are kept active with toys and interactions they should be able to maintain a healthy weight for life. You would need to monitor their body shape (weights are not accurate to determine healthy weight, it is the standard can you see a defined waist and feel but not see bones description) and adjust food/feeding as needed though.

Since mine are all free feeders dry and wet once a day I just change the dry to a lower calorie or reduce portion on the wet depending on which cat or if all are gaining a little weight. I know a lot of people say wet food is best because of kidney issues but I've always had cats who drink a lot so that has never been an issue in my house (highly recommend fountains for this reason). 

Kittens should be fed as much as they want and as often as they want, so if you are not there to serve them many wet food meals, keep the dry food out as you are doing now. They are still growing and require a lot more food and nutrition than adult cats.

BTW, your kittens are absolutely adorable!

I don't agree that kittens should be fed whatever they want. Kitten food is made to provide the protein and fat a kitten needs based on weight. Kittens can be free fed as long as the total amount is what their daily portion should be. As they grow, you monitor their weight and body condition. If they are too thin, increase their intake a bit. If they are too big, decrease their intake a bit. An overweight kitten is not a good start to life. Their bodies aren't fully formed and excess weight will put unnecessary strain on their joints. And excess weight sets them up for diseases, decreased activity and lower quality of life. Personally, I prefer scheduled meals because I know exactly how much my pets are eating or if they stop eating. If I were feeding a kitten this way, I would feed their daily portion divided into 3 or 4 meals, or maybe even 5. I would not just feed on demand however.