The present invention extends to methods, systems, and computer program products for stepping through JavaScript code in a debugger without landing on errors in library or open source code. A debugger receives user inputs designating one or more segments of the JavaScript code as library code. The debugger then performs debugging operations on the JavaScript code. The debugging operations including a stepping operation for stepping through the JavaScript code to identify errors only in user-generated segments of the JavaScript code, wherein the user-generated segments correspond to code that was not designated as library code.