You can not only assume it, but I can also say with certainty it exists. Emscripten hastened this by letting site owners compile little-endian code into little-

You can not only assume it, but I can also say with certainty it exists. Emscripten hastened this by letting site owners compile little-endian code into little-endian asm.js. For example, the WhatsApp Web QR code generator won't run on a BE platform; it's an Emscriptenized blob of code backing it that assumes the typed array it stores into has LE orientation. TenFourFox and Leopard Webkit both emulate little-endian typed arrays on BE Power Macs and transparently byteswap integers. This mostly works for sites that care and has almost no overhead in JITted code for 16 and 32-bit int, but Facebook managed to break some of our assumptions with floats (example: https://github.com/classilla/tenfourfox/issues/453 https://github.com/classilla/tenfourfox/issues/453 -- we don't byteswap floats because it's expensive and probably would break things expecting native endian on the DOM side). Fortunately, TenFourFox doesn't support WebGL, so we don't need to worry about that. IMHO, this is a broken promise about how the Web was supposed to be platform-independent. I get the feeling the general attitude on this thread is that such platforms are unimportant, but that doesn't mean it's not a broken promise.