This depends on the browser. Dev tools are &quot;smart&quot;. It knows where you should put a breakpoint (i.e: putting it on a blank line, it puts it on the next executable line instead). It also knows when you adjusted your script (i.e.: removing a line above, it moves up the breakpoint).<p>&quot;slipping&quot; can happen if:<p>- The dev tools can&#x27;t determine where to move the breakpoint (i.e.: if you significantly changed the file). Just re-assign the breakpoint.<p>- It can also happen when you use a badly-constructed source map. Disable source maps and work with raw code, and contact the tool-maker about this.<p>- Sometimes, the dev tools will just go crazy. Just close and reopen.<p>- debugger. You have no choice.