Some differences between HTML5 and Flash:
=> HTML5 has undoubtedly the biggest potential market reach of any platform.
=> Flash requires an additional plugin to be installed in the browser.
=> Apple doesn’t support Flash.
=> Flash has been termed as being difficult to use on touch devices, slow, battery-draining and insecure.
=> HTML5 is like a lightweight, better supported, faster and open version of Flash.
=> HTML5 runs natively in the browser rather than through a plugin controlled by a corporation.
=> Flash is more popular and more widely used for videos and animation than HTML5.
=> Flash has good audio and video support. HTML5 has varying audio and video support, as browsers all support different combinations of audio and video formats.
=> Flash has mature tools. Adobe's Flash Builder and other tools are powerful and well-supported. HTML5 content can be written in Javascript and HTML.
=> Adobe's tools are also much more expensive than Construct 2 will be. Construct 2 is HTML5 editor.
=> In HTML5, full programmatic access is provided for audio and video playback. However, the issue of supported codec is still being debated.
=> Flash makes it easier to insert ads within videos presented on the Internet.
=> Flash uses more CPU power than HTML5.
=> MP4 or H.264, ogg/Theora and WebM are the three codecs that currently support HTML5.