☛ Selenium is a free and open source. You don't need to spend any licensing cost to use it.

☛ Cross Browser compatibility (Firefox, Chrome, Internet Explorer, Safari etc.)

☛ Multiple programming languages (Java, C#, Ruby, Python, Pearl etc.) support

☛ Compatibility with the main platform (Windows, Mac OS, Linux etc.)

☛ Huge amount user base and helping communities

☛ Automation scripts creating ability for non-programmers as well as for programmers

☛ Testing distribution support

☛ Regular and fresh repository developments