Unity download archive

From this page you can download the previous versions of Unity for both Unity Personal and Pro (if you have a Pro license, enter in your key when prompted after installation). Please note that there is no backwards compatibility from Unity 5; projects made in 5.x will not open in 4.x. However, Unity 5.x will import and convert 4.x projects. We advise you to back up your project before converting and check the console log for any errors or warnings after importing.