[AkshitGarg]

Yep you need to specify the maximum memory amount up-front. Its defined as "webassembly memory pages". Each page is 64kb. You need to specify an initial and a maximum amount. The webassembly module can call memory.grow() to grow it by a page until it reaches the maximum. Though you can't "un-grow" or decrease the amount of allocated memory.

[daniellehmann]

This is not correct, it is not necessary to specify a maximum memory size. See the WebAssembly specification https://webassembly.github.io/spec/core/syntax/modules.html#.... Due to 32-bit address space, the maximum memory is limited to 4GB however.

(In asm.js, memory was provided by an ArrayBuffer of fixed size, so there memory could truly not grow at runtime.)