Generating UUIDs across languages: stdlib vs libraries in 2026

# The short version

Every major language has v4 UUID support — either in stdlib or via a package everyone uses. v7 support is still library-only in 2026, but the libraries are solid.

<div class="callout callout-note" role="note"><div class="callout-title">Note</div><div class="callout-body"><p>Unsure whether you want v4 or v7? <a href="/blog/uuid-v4-vs-v7">UUID v4 vs v7</a> covers the trade-offs. Short answer: v7 for database primary keys, v4 for everything else.</p></div></div>

# JavaScript / TypeScript

Modern browsers and Node 14+ have crypto.randomUUID() — v4 only:

crypto.randomUUID();
// 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

For v7, use the uuid package (v9+):

import { v4, v7 } from "uuid";
v4();  // classic random
v7();  // time-sortable

# Python

Python 3 has uuid in stdlib:

import uuid
str(uuid.uuid4())
# 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

v7 is coming to stdlib in 3.14 (currently a draft PEP). For now, use the uuid-utils package:

from uuid_utils import uuid7
str(uuid7())
# '018f3c9a-1234-7abc-8def-0123456789ab'

# Go

The google/uuid package is the de facto standard. Stdlib doesn't ship a UUID type.

import "github.com/google/uuid"
uuid.New().String()
// v4, random — the most common
uuid.NewV7()
// v7, time-sortable (added in 2024)

# Rust

The uuid crate covers both:

use uuid::Uuid;
Uuid::new_v4().to_string();
// v4, random
Uuid::now_v7().to_string();
// v7, uses current time

Feature flag for v7: uuid = { version = "1", features = ["v4", "v7"] }.

# PHP

Not in stdlib. The community standard is ramsey/uuid:

use Ramsey\Uuid\Uuid;
Uuid::uuid4()->toString();
// v4
Uuid::uuid7()->toString();
// v7 (requires ramsey/uuid 4.7+)

# Database-side generation

Postgres 17 added native v7 support:

-- v4 (available since Postgres 13+)
SELECT gen_random_uuid();
-- v7 (Postgres 17+)
SELECT uuidv7();

MySQL doesn't ship native UUID generation — use the application layer.

SQLite has no native UUID type, so pass a string or randomblob(16):

INSERT INTO t (id) VALUES (lower(hex(randomblob(16))));

# Quick comparison

| Language | v4 location | v7 location (2026) |

|------------|-------------------|--------------------------|

| JavaScript | crypto.randomUUID() stdlib | uuid package |

| Python | uuid stdlib | uuid-utils (→ 3.14 stdlib) |

| Go | google/uuid | google/uuid (same package) |

| Rust | uuid crate | uuid with v7 feature |

| PHP | ramsey/uuid | ramsey/uuid (4.7+) |

| Postgres | gen_random_uuid()| uuidv7() (Postgres 17+) |

# Common bugs

1. Using Math.random() in JS to build UUIDs. It's not cryptographically random. Use crypto.randomUUID() or crypto.getRandomValues().

2. Casting between UUID versions without revalidating. A v4 generator produces version=4 in bit 50; changing that bit breaks the variant field.

3. Serialising UUIDs as strings everywhere. Databases store them more efficiently as 16-byte binary — a UUID column in Postgres, BINARY(16) in MySQL. Strings are 36 bytes; binary is 16.

4. Expecting v7 UUIDs to be strictly monotonic within the same millisecond. The standard guarantees per-ID uniqueness, not per-ms ordering. If you need strict order, use a sequence.

# Generate now

Our UUID Generator produces v4 by default, v7 on a toggle. Bulk up to 1000 at once, copy individually or all together. Everything client-side.

# Related reading

• UUID v4 vs v7: which should you use in 2026?
• UUID Generator