a short length of bicycle chain

A wire with a screw. Like the aviation industry.

Titanium multipurpose carabiner, ruler, wrench, bottle opener, flathead screwdriver. Handy for like $5 a decade ago.

A quick release keychain, it releases from a simple multi purpose carabineer. (Yes I know - the carabineer function is for my belt loop, the quick release is really what it is named for)

I've had the same carabineer for what feels like forever now.

My new place uses an electronic keypad entry and my car only has a fob, so all that's on my keychain is my car fob and a little cute catbus guy because it was a gift and it's super cute

Still just the default one.

I like how everyone's answering another question, like OP asked "What do you keep on your keychain besides your keys?" Because none of those things would hold keys. The hole's too small.

Now, like, the guys saying carabiner clip, you couldn't put keys on something like that, but you could put one on your keychain so you could clip it to your belt. Useful if you want to keep your keys from scratching something in your pocket, I suppose. Also keeps your pockets less cluttered.

I've got three right in front of me. A fourth one is on my AirPods case. So yeah, definitely have them.

As someone who's backpacks and bags always turn into black holes this type of leash with a buckle (idk what it's called) has worked wonders for my sanity.

A cute squirrel that seems all innocent but actually is also a bottle opener

Carabiner on a belt loop

Swivel-Eye Bolt Snap Hook

Brass #2 boat snap

Big chunky carabiner. Also it’s green.

I just have a key ring that I attached my first dog's nametag to. It says Adventure Dog on the front, it's nice.

I have the same keychain from when I was 15, so over 30 years. My buddy had a party at his house and someone left their keys. After about two weeks and no one claiming them I switched my crappy keychain for it and left the keys with him. It’s a fork that the tines have been made into curls, lays flat though. It makes me happy to look at.

weight bearing carbine with like man 20 basic ring with all kinds of keys and do dads and such attached. so like common door, front door, mailbox, bike lock. one has a can opener. oh storage key. just tons.

Snap hook

I made a seine twine monkey’s fist for my keys

I don't have a keychain. I try to avoid keys, and most things I need a key for any more have electronic keys. The few things I need physical keys for any more just have that single key on a lanyard, and I'll just grab that specific key when I need it.

I'd say around 80% of then time, I don't have any keys with me at all.

A little key wallet, keeps the keys from jingling when I walk.

Just a plain ring to minimize the size in my pocketses.

Small load-bearing carabineer, with categorized keys on their own ring. Car keys, house keys, safes, bikes. Just grab the keys you need and go.

Bog standard keyring. To keep everything parallel, the folding multitool gets a tiny sub-keyring and the metal USB stick gets a tiny carabiner (detaches to avoid load-bearing USB ports). Keychain goes in a velcro pouch that also holds a multi-tool pen, mini flashlight, and lighter. Pouch goes into front left pocket.

Transportation keys (car or bike locks) are each on their own key ring and I take the one I need. All the rest go in my wallet.