It would depend which type of vital records (birth, death, or marriage), which time period, and which state the events took place in. Some records are available for certain time periods and states on familysearch.org. A few state archives have some records available online. Other states have few if any records available on-line and to obtain official copies would involve a fee.
Welcome to History Hub
FREE: IS THAT A WORD..."JUST KIDDING"
familysearch.org is an "ALWAYS FREE" website, you just need to register to search. You can find SOME birth, death, and marriage records there.
Then there are the sights that give you a one time FREE trial , like Ancestry.com, they have some vital records and you might find vital records that other relatives have found and posted.
Newspapers.com gives a one time FREE trial, you might find birth announcements and obituaries and marriages on there
Some libraries let you search genealogy websites if you have a library card. Check with your local library.
Good Luck in your search.