Ancestry.com and Recordsbase.com have searchable databases of historical marriage records, and each usually allows a free trial period when first registering. Many county clerk offices also maintain websites or allow records requests via email for older records. However, for copies of recent records, clerk's offices usually charge.
Many other online services can help with searches for marriage licenses and other public records, but most charge a fee. Ancestry.com's extensive database is effective for searching historical marriage records, both in the U.S. and worldwide. If searching for marriage records on an ongoing basis and in multiple locations, a fee may be payable.