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Remove fl.js for better JS performance

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All the banners I server are either images or HTML and there is 0% chance I serve flash.

While doing a performance review of my JS code I noted the standard Revive JS code (served via /asyncjs.php) contained a whole section of JS referencing ShockwaveFlash.ShockwaveFlash

Checking the asyncjs.php source I see it includes a reference to a required flash config file (fl.js in the /www/delivery folder)

require __DIR__.'/'.$GLOBALS['_MAX']['CONF']['file']['asyncjsjs'];
require __DIR__.'/'.$GLOBALS['_MAX']['CONF']['file']['flash'];

I currently commented out the inclusion of the fl.js so the JS is smaller. All seems to work fine.


  • asyncjs.php goes from 3.6KB to 2.0Kb when transferring over the wire (GZIP). (not massive, but with Chrome never slow mode, you only have a certain budget of JS available. Saving 1.6Kb here can help to stay under the 500kb limit)
  • 9883 bytes to 42993 bytes in unzipped format. (this is less JS code to parse/execute. Read The Cost Of JavaScript In 2018 for more details https://medium.com/@addyosmani/the-cost-of-javascript-in-2018-7d8950fbb5d4


My 3 questions for the community are?

  • Do you know any side effects of removing the fl.js inclusion? 
  • Are there better options than commenting it out?
  • Are there other JS optimisations you are aware off?

Thank you



Edited by scalemates
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