Google webmasters tool is showing me 26 duplicate pages because you can access the page
in both ways:
/crossMaker.php?jsonID=103
/crossMaker?jsonID=103
In my htaccess file i made it possible not to include the php extension but
probably somewhere in the code i linked to the filename with the suffix so google crawled
it.
What can i do so that google will forget about the file with the extension? use 301 redirect? if so how do i do that?
Just use canoncial URLs. It’s much easier and the proper way to handle this.
For example, put this at the top of the page:
You can create these dynamically so it should be easy for you to implement.