you can't, they are not interchangeable. the big converters out there simply strip assets (images, vectors) and port them over to a canvas. all your actionscript 2 is garbage at this point. you have to relearn a new language and build from the ground up. actionscript 3 used to be "semi-convertible" because it was similar to javascript, however any and all services like swiffy no longer support this because the results were too incompatible. best bet is to learn javascript and start fresh. but fear not, MS and Google have formally established to permanently maintain flash player (because services like amazon still use it internally for their cataloging, and to replace this will be a HUGE security risk since HTML5 has what are known as "permanent holes" that can't be patched (lest they break functionality of the language as a whole). so if you have a flash site, simply employ an HTML5 popup that alerts users to whitelist you or enable flash player per visit. TLDR; continue to use flash because big corporations are paying for its extended support for many years to come.