Detect WebAssembly Features

A tiny, zero-dependency library for detecting WebAssembly features (~2 kB minified).

Support features

• [x] Reference types (standardized)
• [x] BigInt between js and wasm (standardized)
• [x] Bulk memory operations (standardized)
• [x] Exceptions (--experimental-wasm-eh)
• [x] Memory 64-bit (--experimental-wasm-memory64)
• [x] Custom page sizes
• [x] Mutable globals (standardized)
• [x] Multi values (standardized)
• [x] Saturated (non-trapping) conversions from float to int (standardized)
• [x] Sign extensions (standardized)
• [x] Tail calls (--experimental-wasm-return-call)
• [x] Threads (standardized)
• [x] SIMD (standardized)
• [x] Relaxed SIMD
• [x] GC
• [x] Type reflection (--experimental-wasm-type-reflection)
• [x] Typed function references
• [x] JS String builtins

Install

yarn add wasm-check

or

npm i wasm-check

Usage

Check supported WebAssembly version

import * as check from 'wasm-check';
// or
// const check = require('wasm-check');

console.log(check.support());  // WebAssembly >= 1.0
console.log(check.support(1)); // ^^^
console.log(check.support(2)); // WebAssembly >= 2.0
console.log(check.support(3)); // WebAssembly >= 3.0

Check supporting streaming compilation

import * as check from 'wasm-check';

console.log(check.supportStreaming);

Get all post-MVP WebAssembly features

import * as check from 'wasm-check';

const features = { ...check.feature };
console.log(features);

Output:

{
  bigInt: true,
  bulk: true,
  exceptions: true,
  memory64: true,
  customPageSizes: false,
  mutableGlobal: true,
  multiValue: true,
  saturateConversions: true,
  signExtensions: true,
  tailCall: true,
  threads: true,
  simd: true,
  relaxedSimd: true,
  gc: true,
  references: true,
  typeReflection: false,
  funcReferences: true,
  jsStringBuiltins: true
}

Or check concrete feature

import * as check from 'wasm-check';

console.log(check.feature.simd); // has SIMD support?
console.log(check.feature.relaxedSimd); // has Relaxed SIMD support?
console.log(check.feature.tailCall); // has tail call support?
console.log(check.feature.gc); // has Wasm GC support?
console.log(check.feature.jsStringBuiltins); // has JS String builtins support?