When it comes to giving money away online, Seattle was the most generous last year among U.S. cities with populations of more than 100,000, according to a new analysis by a Charleston software firm.

Blackbaud Inc. said Thursday it based the findings on 2013 web-based donations that were processed using the Daniel Island-based company's fundraising technology.

Seattle took the top spot with $53.5 million in online largesse for every 1,000 residents. The top 10 was rounded out by:

Alexandria, Va.

Atlanta

Washington, D.C.

Cambridge, Mass.

Ann Arbor, Mich.

Arlington, Va.

Cincinnati

Bellevue, Wash.

San Francisco

Now in its sixth year, the Blackbaud study analyzed 265 cities that gave away a total of about $822 million last year.

South Carolina had two representatives on the most-generous list, including the software firm's home town: Columbia and Charleston were ranked 41st and 51st, respectively, with $13.8 million and $12 million in donations per 1,000 residents.

Blackbaud's software and services are designed specifically for nonprofits to help them connect with donors and raise money more effectively.

"Online giving continues to be an important part of a nonprofit's overall strategy," said Steve MacLaughlin, the company's director of product management. "We continue to see growth in online giving and it is helping to drive fundraising results across nonprofits of all sizes."

Contact John McDermott at 937-5572.