How to Generate UUID in Go

How to Generate a UUID in Go

Install github.com/google/uuid, the community-standard package for UUID generation in Go, then call uuid.New() to get a random v4 identifier — it's the fastest way to add unique IDs to structs, database rows, or API responses. Use the typescript uuid guide to implement type-safe UUIDs in TypeScript with strict compile-time checking.

Terminal

go get github.com/google/uuid

main.go

package main

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

func main() {
    id := uuid.New()
    fmt.Println(id.String())
    // Output: 550e8400-e29b-41d4-a716-446655440000

    // Or handle the error explicitly
    id2, err := uuid.NewRandom()
    if err != nil {
        panic(err)
    }
    fmt.Println(id2)
}

Explanation

go get github.com/google/uuid adds the package to your module — Go's standard library has no built-in UUID generator.
uuid.New() generates a random version 4 UUID and is safe for virtually every use case, since it only panics if the system's random source itself fails.
uuid.NewRandom() does the same thing but returns an explicit error instead of panicking, letting you handle a failed random read gracefully in code that can't risk a crash.
id.String() and Go's fmt.Println both call the UUID type's Stringer implementation, producing the standard 36-character hyphenated form.

Convert a String to a UUID in Go

When a UUID arrives as a string — from a URL path, a JSON body, or a database column — parse it back into a type-safe uuid.UUID with uuid.Parse() so you can compare, store, or validate it like any other Go value. The dart uuid reference explains how to use Uuid().v4() for random UUIDs and v5() for name-based generation.

main.go

package main

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

func main() {
    id, err := uuid.Parse("550e8400-e29b-41d4-a716-446655440000")
    if err != nil {
        log.Fatal("invalid UUID:", err)
    }
    fmt.Println(id)

    // MustParse panics on invalid input - use only for
    // hardcoded constants or tests, never on user input
    fixed := uuid.MustParse("550e8400-e29b-41d4-a716-446655440000")
    fmt.Println(fixed == id)
}

Explanation

uuid.Parse() returns a (uuid.UUID, error) pair, so a malformed string never crashes your program — you always get the chance to handle the error.
The parser accepts the standard hyphenated form as well as unhyphenated hex, URN format, and Microsoft's bracketed GUID style.
uuid.MustParse() skips the error check and panics immediately on invalid input, which is convenient for constants and test fixtures but unsafe for anything coming from a request or config file.
uuid.UUID values compare directly with == because the type is a plain 16-byte array under the hood.

Other Options for Generating UUIDs in Go

uuid.New() covers most cases, but github.com/google/uuid v1.6+ also ships uuid.NewV7(), which generates an RFC 9562-compliant time-sortable UUID — a better fit for database primary keys than a fully random v4.

main.go

package main

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

func main() {
    // Unix-timestamp-prefixed, sortable, index-friendly
    id, err := uuid.NewV7()
    if err != nil {
        panic(err)
    }
    fmt.Println(id)
}

Explanation

uuid.NewV7() was added in google/uuid v1.6, so run go get -u github.com/google/uuid if your go.mod pins an older version.
A v7 UUID encodes the current Unix millisecond timestamp in its leading bits, so IDs generated later always sort after earlier ones — unlike v4, which is fully random.
Sortable IDs keep database B-tree indexes more sequential than random v4 keys, reducing page splits and improving insert performance at scale.
v7 still includes enough random data to stay collision-resistant, so it's safe to use as a public-facing primary key.

Generate UUID in Go

How to Generate a UUID in Go

Explanation

Convert a String to a UUID in Go

Explanation

Other Options for Generating UUIDs in Go

Explanation

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