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How to use time.Sleep in Go (Golang) to pause execution

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Basics Time Sleep Duration

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The time.Sleep function pauses the current goroutine for a specific duration. It is the simplest way to delay execution in Go and is built into the standard time package. ⏱️

What is time.Sleep? #

time.Sleep(d time.Duration) blocks the current goroutine for d. The duration is expressed as a number multiplied by a time unit, like 500*time.Millisecond or 2*time.Second.

Common units:

  • time.Nanosecond
  • time.Microsecond
  • time.Millisecond
  • time.Second
  • time.Minute
  • time.Hour

When to use time.Sleep #

Use it for short, controlled delays such as:

  • Simulating network latency in a demo
  • Spacing out retries with a fixed delay
  • Pacing log output in CLI tools

How to pause execution with time.Sleep #

This full program prints a message, sleeps for 3 seconds, and continues:

package main

import (
    "fmt"
    "time"
)

func main() {
    fmt.Println("before Sleep()")

    time.Sleep(3 * time.Second)

    fmt.Println("waking up after Sleep()")
}

Common mistakes #

❌ Using plain integers without a unit:

time.Sleep(3) // sleeps for 3 nanoseconds, not 3 seconds

✅ Always multiply by a time unit:

time.Sleep(3 * time.Second)

❌ Using time.Sleep to coordinate goroutines:

time.Sleep(100 * time.Millisecond) // unreliable synchronization

✅ Use channels, sync.WaitGroup, or context for coordination.

Best practices #

  • Keep delays explicit and small; prefer time.Duration variables for clarity.
  • If you need timeouts, use context or time.Timer instead of hard sleeps.
  • Document why the delay exists to avoid accidental removal. ✅

Tested with Go 1.25+ | Last verified: December 2025 🎉