How to Call JavaScript from Go Wasm

You call JavaScript from Go WebAssembly by using the syscall/js package to reference a global JavaScript object and invoke its methods.

package main

import (
	"syscall/js"
)

func main() {
	window := js.Global().Get("window")
	window.Call("alert", "Hello from Go!")
}

Compile your Go code with GOOS=js GOARCH=wasm go build -o main.wasm and load the resulting .wasm file in a browser using a Go runtime loader.

Calling JavaScript from Go Wasm allows your Go program running in a web browser to talk to the browser's built-in JavaScript features. Think of it as a bridge where Go sends a message to JavaScript to perform an action, like showing a pop-up alert or reading a value from the webpage. You use this whenever your Go code needs to interact with the user interface or browser APIs.