The Epic Unreal Engine Blog lists the HTML5 size as: “9.4 MB”, however when I load Tappy Chicken in Chrome with the Developer Tool open, I see the following files loaded when I hit start:
TappyChicken.data is just that, game data. You still need the engine itself which is the other two files in order to play the game. Since Epic does not ship a plugin like Unity does, but runs through HTML5 and asm.js, it has to load the engine from the Web.
It is possible/likely that the two engine files get cached in the browser and are re-used on consequent page loads but you just can’t escape this.
Android and iOS probably do include the engine (did not personally verify though), but HTML5 is still a work in progress. You can see changes happening in the engine source all the time on github.
I believe Epic did mention that they will be optimizing the file sizes further more for HTML5.
I think you are mistaken - these files are compressed javascript - if you look at the sizes within - chrome - It will respond with the “uncompressed size”
eg - if you download these files with lets say wget or curl, the “ACTUAL” size of the file which is downloaded is much smaller.
UE4Game-HTML5-Shipping.js.jgz is ~7.25MB
TappyChicken.data.jgz is around 1.2MB
.mem file is around .7 MB.
Hence the total download size is actually 9.4 MB! the sizes to which are uncompressed by the browser is sort of tangential to the download size.