- Supported technologies, does it support AJAX, Silverlight, FLASH, java applications, .NET applications, etc... Choose the one the supports your applications
- Required environment to run the automated tests, can you have it?
- Cost
- Ease of use, does it require specific training, can you record some of the steps
- Coding language used, is it easy to learn, does it have support, communities
- Flexibility, can you write custom code to do custom tasks, can you connect to database, etc... Better to use the ones that use common languages, like JAVA, .NET, javascript, Paython