How old should kids be before hunting solo?

No specific age,MATURITY is the important factor.

My dad cut me loose when i was 12. I cut my son loose when he was 12. Starting to sense a pattern here.

It looks like everyone has said what I was going to say it's maturity & hunting experience that determines the age of when solo hunts should start.
I wasn't as fortunate as the others I taught myself to deer hunt. I had been out squirrel hunting with my brothers when I was about 10 but I didn't pick up on hunting again until my late 30s early 40s when a buddy wanted to take me deer hunting.

Yes you will always worry about them but if you have done your best to teach them everything you know. With a few seasons under their belt I'm sure they have picked a few tricks on there own so it is possible that they are a better hunter than we are.
The only things I would add is this at times can be a physically demanding sport, be sure they are up to the physical demands.
And most important stay in communication with them just in case they get into a jam.

I was on my own from the get go. No one in my family hunted. My best friend had lots of property but no one that hunted so we did lots of small game starting at 10 yrs old limited to walking distance. By 12 we would be dropped off and picked up later. I turned 16 and bought a bow then began hunting deer.

I agree it would all depend on the experience and maturity of the kid. I would let my 11 yr old walk around out back but not hunt out of a tree stand. My 13 yr old maybe. Neither one wants to hunt though.

When ever you'd feel safe handing them a gun and leaving them at home alone.

I did when I was 12 along with (what seems to be) everyone else. But this is my first season truly hunting by myself (17) I.e. Hanging stands, cameras, some food plots, etc.

My dad let us go with him when we were 13 the first time hunting different species but after the first time if we wanted to go by ourselves we could. He would take us the first to show us and explain to us how to do it for that particular animal. We would still hunt together some but we also would hunt solo,just depended on if he could or wanted to. I basically did the same thing with my boys but living in town they couldn't go unless I drove but we still would hunt different areas of the same property some and also together some if we ran into each other. Back when I started we didn't hunt deer though,it was all small game,furbearers or birds,but with my boys it was just squirrel and rabbit. My oldest son lost interest in hunting after a couple of years and my youngest didn't get into deer hunting until after he became an adult. We sort of go deer hunting together some,he comes out but we drive our own vehicles and park on opposite sides and leave at different times but text each other on what we're seeing and help each other load them if we get 1.

My family is 13 yrs old. Same for me and my sons.

I have, on numerous occasions, driven to my property and just sat in the truck, without dad knowing it, while he hunted.

Just in case.