Various technologies and techniques are disclosed for creating interruptible client-side scripts. Input is received from a developer to write original code for a web application in at least one client-side script. A code injection process is programmatically performed to modify the original code to make one or more parts of an execution of the code interruptible in the client-side script. The code injection process parses a code segment of a client-side script to retrieve a next code segment. If the next code segment has at least one conditional semantic construct, then code is injected in the form of one or more script functions that will transition execution flow from the original code segment into the one or more script functions that are operable to interrupt execution of the client-side script upon user request. The modified code resulting from the code injection process is saved for the web application.