Constructive Criticism for WebAssembly Binaries
Pick a WebAssembly file:

Or enter a URL of a WebAssembly file (will fail without CORS; for a test, try "opt.wasm" or "unopt.wasm"):



When given a WebAssembly file, this site will try to shrink it down to a smaller size. It will report whether it succeeded, and if so, will let you download that optimized binary.

This runs Binaryen's wasm-opt tool. wasm-opt has many optimizations that can improve WebAssembly files' size and speed.

Note that there is no server component! Everything here runs on the client, right here on the page.

This may be slower than running wasm-opt locally for a few reasons:

  • This currently uses only a single core (binaryen will normally automatically parallelize to use as many cores as you have, for an almost linear speedup).
  • WebAssembly doesn't have native exceptions support yet.
On large wasm files you may prefer to run locally for speed.