# Regarding Manifest file **URL:** \ **Category:** Questions\ **Created:** [August 20, 2018, 12:13pm UTC](https://forum.defold.com/t/regarding-manifest-file/27740 "2018-08-20T12:13:04Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![Mathias\_Westerdahl](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/mathias_westerdahl/32/228_2.png) [@Mathias\_Westerdahl](https://forum.defold.com/u/Mathias_Westerdahl)\ **Post date:** [August 20, 2018, 4:15pm UTC](https://forum.defold.com/t/regarding-manifest-file/27740/4 "2018-08-20T16:15:01Z")
On the other platforms, the vpx library is fairly big. But on HTML5, it doesn’t exist so you won’t save any memory on that. To be clear, don’t you get _any_ size change at all? Have you specified the manifest in the `game.project`? > [@Native Extensions](https://forum.defold.com/t/native-extensions/4946/133): > > Of course! I got so excited about the release I had forgot to prepare my notes… ^^ Customizing the engine build Apart from specifying your own new extensions, you can also enable/disable libraries via the “App Manifest” This is a feature that has very little documentation yet (none?). The basic idea is that it should work very closely to how the extension manifest works (and also our master config for the server). And although this config design isn’t fully nailed down, we think it’s benef… In the future, we’ll make it possible to exclude either 2d or 3d physics (now they’re lumped together) --- _[View the full topic](https://forum.defold.com/t/regarding-manifest-file/27740)._