The web is now the dominant platform for software development and thishas fostered the development of load testing services on the web. The Software Testing Magazine website has published article that presents some free offers from commercial web load testing services providers.
Most of these free Web load testing services have limitations that concern the number of virtual users, the duration of the tests, the number of tests and the ability to test from multiple geographical locations. If some vendors put explicit values on each of these items, other are working with a credit system that you can apply to multiple configurations.
Read the complete article on http://www.softwaretestingmagazine.com/knowledge/free-web-load-testing-services/