I tried many ways to check addresses that start with 3 if it's segwit or not but I couldn't find any tool that can check the address if it's segwit or not.
Except to those addresses that already have spent transactions.
Like this one
I use blockchair.com to check them to do that you need to check that address on the blockchair and look for sent click the hash it should show segwit on the right side of transaction status.
Another alternative is to use https://coinb.in/#verify you must copy the raw/hex code of the sent transaction and paste it there. Then if the segwit shows true under the transaction script it means the address is segwit.
Except to those addresses that already have spent transactions.
Like this one
I use blockchair.com to check them to do that you need to check that address on the blockchair and look for sent click the hash it should show segwit on the right side of transaction status.
Another alternative is to use https://coinb.in/#verify you must copy the raw/hex code of the sent transaction and paste it there. Then if the segwit shows true under the transaction script it means the address is segwit.