Generate UUID in Go

Q: What is the best UUID package for Go?

github.com/google/uuid is the de-facto standard. It is maintained by Google, widely used in production, and supports UUID v1, v4, v6, and v7. Install with: go get github.com/google/uuid

Q: How do I use a UUID as a primary key in GORM?

Embed a uuid.UUID field with a BeforeCreate hook to auto-assign it, or use a custom type that implements the gorm.Valuer and sql.Scanner interfaces. The google/uuid package's UUID type implements database/sql interfaces natively, so it works with GORM out of the box.

Use github.com/google/uuid — the standard UUID library for Go. Covers v4, v7, GORM models, and HTTP handler patterns.

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Open UUID v4 Generator →

The Quick Answer

Go's standard library doesn't include a UUID package. Use github.com/google/uuid — the widely accepted community standard.

Terminal — install

go get github.com/google/uuid

Go — generate UUID v4

package main

import (
    "fmt"
    "github.com/google/uuid"
)

func main() {
    id := uuid.New()  // UUID v4
    fmt.Println(id.String())
    // → "f47ac10b-58cc-4372-a567-0e02b2c3d479"

    // As string directly
    idStr := uuid.NewString()
    fmt.Println(idStr)
}

UUID v7 in Go (Time-Ordered)

UUID v7 is sortable by creation time and avoids B-tree fragmentation in databases. The google/uuid package supports it from v1.6+.

Go — UUID v7

import "github.com/google/uuid"

id, err := uuid.NewV7()
if err != nil {
    // error only if random source fails
    panic(err)
}
fmt.Println(id.String())
// → "0190c0a7-73b7-7000-b7c8-4b4aabd7e00e"
// First segment is a millisecond timestamp — rows sort naturally.

GORM — UUID as Primary Key

Go — GORM model with UUID primary key

package model

import (
    "github.com/google/uuid"
    "gorm.io/gorm"
)

type Product struct {
    ID   uuid.UUID `gorm:"type:uuid;primaryKey"`
    Name string    `gorm:"not null"`
}

func (p *Product) BeforeCreate(tx *gorm.DB) error {
    if p.ID == uuid.Nil {
        p.ID = uuid.New()
    }
    return nil
}

HTTP Handler Pattern

Go — parse UUID from URL path

package main

import (
    "net/http"
    "github.com/google/uuid"
)

func getItem(w http.ResponseWriter, r *http.Request) {
    rawID := r.PathValue("id")  // Go 1.22+ stdlib routing
    id, err := uuid.Parse(rawID)
    if err != nil {
        http.Error(w, "invalid UUID", http.StatusBadRequest)
        return
    }
    // id is now a validated uuid.UUID
    _ = id
}

Frequently Asked Questions

What is the best UUID package for Go?

github.com/google/uuid is the de-facto standard. It is maintained by Google, widely used in production, and supports UUID v1, v4, v6, and v7. Install with: go get github.com/google/uuid

Is there a built-in UUID generator in Go's standard library?

No. Go's standard library does not include a UUID package. The crypto/rand package provides the underlying randomness but you still need to build or import the UUID format logic. Use github.com/google/uuid rather than rolling your own.

How do I use a UUID as a primary key in GORM?

Embed a uuid.UUID field with a BeforeCreate hook to auto-assign it. The google/uuid package's UUID type implements database/sql interfaces natively, so it works with GORM out of the box.

Should I use uuid.New() or uuid.NewString() in Go?

Use uuid.New() when you need the uuid.UUID type (e.g. to pass to a function, store in a struct, or use with GORM). Use uuid.NewString() when you only need the hyphenated string representation and want to skip the intermediate .String() call.

Generate UUID in Go

The Quick Answer

UUID v7 in Go (Time-Ordered)

GORM — UUID as Primary Key

HTTP Handler Pattern

Frequently Asked Questions

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UUID v4 vs v7