UUID Hyphen Converter

The RFC 4122 and RFC 9562 Canonical Layout

The canonical representation separates 32 hexadecimal digits into 5 hyphen-delimited segments formatted as 8-4-4-4-12:

xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
|      | |  | |  | |  | |          |
time_low |    |    |  | node (48-bit)
     time_mid |    clock_seq_hi / variant (N)
          time_hi / version (M)

In modern UUID variants such as UUID v4 (pseudo-random) and UUID v7 (Unix Epoch time-ordered), these hyphen positions are retained strictly for backward compatibility with parsers expecting the 36-character format.

Storage Efficiency Across Databases

Choosing whether to store UUIDs as hyphenated strings, compact hex, or raw bytes has dramatic impacts on B-Tree index performance and disk consumption:

Programmatic Code Snippets

To perform these conversions in your application backend without external libraries:

Node.js / TypeScript

// Remove hyphens (canonical to compact)
const compact = uuid.replace(/-/g, '');

// Add hyphens (compact to canonical)
const canonical = compact.replace(/^([0-9a-f]8)([0-9a-f]4)([0-9a-f]4)([0-9a-f]4)([0-9a-f]12)$/i, '$1-$2-$3-$4-$5');

Python

import uuid

# Parse any format and output compact or canonical
u = uuid.UUID("123e4567-e89b-12d3-a456-426614174000")
compact = u.hex        # '123e4567e89b12d3a456426614174000'
canonical = str(u)     # '123e4567-e89b-12d3-a456-426614174000'
binary = u.bytes       # 16 raw bytes for database insert

MySQL 8.0+

-- Insert as optimal BINARY(16) with time-ordered swapping
INSERT INTO users (id, name) VALUES (UUID_TO_BIN('123e4567-e89b-12d3-a456-426614174000', 1), 'Alice');

-- Retrieve as standard hyphenated string
SELECT BIN_TO_UUID(id, 1) AS id, name FROM users;