Bitcoin Forum

I'm curious if there is an easy way to find out if bitcoins that were at a specific address made it to another specific address.  Like if I have an address now that I want to know if it has a connection to an address that was made 2 years ago.  Are there any online tools where you can put in 2 addresses and it will attempt to find a connection between them? 

Thanks.

https://www.walletexplorer.com is the only thing i can think of, it doesn't have the option to enter 2 addresses, you will have to search for them individually and see the links.
there was also a block explorer which showed a visualization of the entire transaction history of each address which could be used to find the links but i can't seem to find it anymore. maybe it was blockchain.info and removed that option. does this remind anybody of anything?

Finding a connection between two address is the same problem as finding if there is a path between two nodes in a cyclic directed graph. Unfortunately the runtime complexity is linear (see A* or Dikstra's algorithm), and given that there are about 500 million trx and another 1 billion unique addresses used means finding a path can last from minutes to hours.
So you are unlinkely to see a website offer this service, your best bet is to set this up locally on your machine if your hardware is good enough and run the algorithm yourself.

Bitcoin is traceable but pseudonymous.
So it varies from user to user, some know how to hide and the other can link their own addresses through the use of any explorer.
I found this thread on Reddit^[1], and this tool^[2] you will not lose anything if you try it.
Generally, if you are willing to pay some money, creating a topic in the services section may help.

[1] https://www.reddit.com/r/Bitcoin/comments/5t6ww2/find_connections_between_bitcoin_addresses/ddlyy70/
[2] https://learnmeabitcoin.com/browser/node/

Just remember when people use mixer services, that link is broken and you will not be able to link the two addresses with the sites that was mentioned in the previous posts.

There are companies specializing is Blockchain analysis, but it is not clear if they can link addresses, once it is pushed through Mixer services. < https://www.chainalysis.com >

Why do you need this information?

Every generated bitcoin address is unique. So how you are wondering to find connection with 2 years old address if have not made any transaction. As @pooya87 mentioned you will find there is any address belongs to same wallet or if there is any transaction made between 2 wallets. Otherwise you will not able to find any connection. A fresh address belongs to a wallet and if wallet is new created by you then I don't think you will able to find any connection with 2 years old address or wallets.

They can and it is often somewhat trivial due to faulty/ignorant setups/algorithms used by mixers. Use Wasabi if you need to mix. Just FYI for your future responses.