About the game dev tools
Game engines want textures in formats the graphics card can read directly. DDS holds blocks compressed as BC1 through BC7 with a mipmap chain built in, so the card can sample a small version at distance without extra work; TGA stores plain lossless pixels with a clean alpha channel, which is why Unity, Unreal, Source, and Blender pipelines have never dropped it. Browsers open neither, so the viewer and converters here decode them with a Rust module compiled to WebAssembly.
The rest of this page is for making assets rather than converting them: a pixel-art editor with layers and frames, a seamless noise generator, a normal-map generator, sprite sheet tools, and a set of Minecraft editors for skins, resource packs, banners, and commands. Nothing here ships game assets; the editors start from your own files.