Golang InkWasm

InkWasm is faster syscall/js replacement, it’s a package and a generator. Our goal is to be as faster and avoid unnecessary allocations. InkWasm initially created for Gio, improving the performance for WebGL API, in some devices and tests InkWasm is 2x faster than syscall/js, in real application it’s 1.6x faster.

⚠️ The generator changes the file of the current packages and imported packages. It is still experimental, keep a backup file and use some versioning tool (like Git).


The performance may vary based on how you use syscall/js and InkWasm. Look into inkwasm/tests_js_test.go for more details.

Benchmark_DOM_INKWASM                       50000        11462 ns/op         52 B/op         1 allocs/op
Benchmark_DOM_RUNTIME_INKWASM               50000        14934 ns/op        100 B/op         4 allocs/op
Benchmark_DOM_BAD_RUNTIME_INKWASM           50000        18302 ns/op        100 B/op         4 allocs/op
Benchmark_DOM_JS_SYSCALL                    50000        23550 ns/op        167 B/op        11 allocs/op
Benchmark_DOM_BAD_JS_SYSCALL                50000        30540 ns/op        175 B/op        12 allocs/op

Benchmark_BytesRandom_INKWASM              100000         1026 ns/op          0 B/op         0 allocs/op
Benchmark_BytesRandom_JS_SYSCALL           100000         1808 ns/op         40 B/op         3 allocs/op

Benchmark_SetLocalStorage_INKWASM          854655         6312 ns/op          0 B/op         0 allocs/op
Benchmark_SetLocalStorage_JS_SYSCALL       486326        11796 ns/op         64 B/op         4 allocs/op

Benchmark_GetLocalStorage_INKWASM         1830148         3300 ns/op          4 B/op         1 allocs/op
Benchmark_GetLocalStorage_JS_SYSCALL       826088         7356 ns/op         48 B/op         6 allocs/op

Benchmark_GetLocationHostname_JS_SYSCALL  3038510         1979 ns/op         32 B/op         2 allocs/op
Benchmark_GetLocationHostname_INKWASM     2499522         2442 ns/op         16 B/op         1 allocs/op

Currently, InkWasm is used in one fork of Gio, you can test it online here.

Chrome 98 @ Ryzen 3900X Chrome 98 @ Xiaomi Note 9 Safari 15 @ MacBook Air
[email protected] ~4.65ms ~31.91ms ~5.58ms
github.com/inkeliz/[email protected]_inkjs ~3.02ms ~20.03ms ~4.84ms

The performance improvement varies from 13% up to 37%. You can test it online, and compare the performance on your machine. Want to know how it was implemented? Check it here.


In order to use the generator, you must create one func without body and describe what is the JS function (or attribute) that imports the function.

func main() {
    alert("Your String")

//inkwasm:func globalThis.alert
func alert(s string)

You should run: go run github.com/inkeliz/go_inkwasm build .. It will create a new wasm-build folder, you can run npx serve ./wasm-build and run it on browser.

The generator is faster, but you can also use the inkwasm on “runtime”, similar to syscall/js:

func main() {
    alert := inkwasm.Global().Get("alert")
    defer alert.Free()


Usually, it still faster than syscall/js and have less allocations.

Calling static functions:

You can invoke functions that are “hardcoded”, for instance alert:

//inkwasm:func globalThis.alert
func alert(s string)

func main() {

It will call globalThis.alert.

Calling dynamic functions:

You can also call functions that belongs to a specific Object, the name must start with .:

//inkwasm:func .bufferData
func glBufferData(o inkwasm.Object, target uint, data []byte, usage uint)

func main() {
    glBufferData(gl, len(data), STATIC_DRAW, data)

It will call o.bufferData (is expected that the given o (inkwasm.Object) is a WebGL Context).

Get attribute:

In order to get a attribute use inkwasm:get:

//inkwasm:get globalThis.location.hostname
func getHostname() string

Set attribute:

In order to set attribute use inkwasm:set:

//inkwasm:set .innerHTML
func setInnerHTML(o inkwasm.Object, v string)


Currently, InkWasm is very experimental and WebAssembly, in general, is also very experimental.

  • Calling JS functions (inkwasm:func)

  • Get JS property (inkwasm:get)

  • Set JS property (inkwasm:set)

  • Support integers input (uint, int, int64, …)

  • Support integers output (uint, int, int64, …)

  • Support floats input (float64, float32)

  • Support floats output (float64, float32)

  • Support slices/array input (string, []byte, []float64, [10]byte, …)

  • Support slices/array output (string, []byte, []float64, [10]byte, …)

  • Support big integers input (big.Int)

  • Support big integers output (big.Int)

  • Support channels input (chan string, …)

  • Support channels output (chan string, …)

  • Support complex input (complex64, complex128)

  • Support complex output (complex64, complex128)

  • Support functions input (func(){})

  • Support TinyGo

  • Export struct (inkwasm:export)

  • Export functions (inkwasm:export)

  • Export alias type (inkwasm:export)

  • Exported functions without js.FuncOf

  • Import custom scripts (*_js.js) into wasm.js.

  • Use -overlay on cmd/go.

  • Improve tests


  • CallImport will be removed:

    Currently, InkWasm heavily rely on CallImport, it will be removed in the future and will be exclusive to syscall/js and runtime golang#38248. If that happens, the only solution is to replace syscall/js, maybe using -overlay on cmd/go.

  • go:wasmexport isn’t (yet) supported:

    Currently, the only way to export function is using syscall/js. However, that is quite slow. We can hack into runtime and syscall/js to be able to replace js.FuncOf. However, I’m waiting to see the progress of the proposal (golang#42372).


The current API is supposed to be backward compatible with any future update. However, the InkWasm may not work on older versions of Golang and the idea is to be compatible with the latest golang version.


Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.




View Github