Images (sprites and backgrounds)

Format Description
.jpg For backgrounds and other images without transparent parts.
.png For sprites and other images with (semi-)transparent parts.
.jng Hybrid format combining the compression of .jpg with support for transparency. Very few image editors directly support this format, but NVList’s image optimizer (work in progress) can generate these for you.
.ktx Uncompressed image data. Images of this type take a large amount of disk-space, but are very fast to load. KTX files are assumed to use premultiplied alpha.

Audio (music and sound effects)

Format Description
.ogg Vorbis audio. Free to use and offers a good balance between audio quality and file size.
.mp3 The popular lossy audio format.


Format Description
.webm VP8/VP9 video, with Vorbis audio.