Goroutines Explained 🚀

Concurrency that costs almost nothing to start.

Marcelo Domingues

1 min read

·

5 days ago

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Want to run something concurrently in Go? Put go in front of it. Done.

What is a goroutine?

A goroutine is a lightweight thread managed by the Go runtime. They start with a tiny stack (a few KB) and grow as needed, so you can spawn thousands without breaking a sweat. The scheduler multiplexes them onto OS threads for you.

Starting one

package main

import (
	"fmt"
	"sync"
)func main() {
	var wg sync.WaitGroup
	for i := 0; i

Watch out

main returning kills every goroutine, so coordinate with sync.WaitGroup or a channel. Goroutines run independently. Use channels or mutexes to share data safely. Capture loop variables explicitly (pass i as an argument) unless you're on Go 1.22+.

TL;DR: go f() launches concurrent work; use WaitGroup or channels to wait for it.

Try spawning 1,000 goroutines and watch how fast they finish. 🐹