UUID & Identifier Studio

About UUID & Identifier Studio

Universally Unique Identifiers (UUIDs) and specialized unique identifier formats — such as UUID v4, time-ordered UUID v7, ULID, NanoID, and CUID2 — are foundational building blocks in modern distributed architecture, database design, and cloud applications. Whether you need random 128-bit RFC 4122 UUID v4 identifiers, time-ordered B-Tree friendly RFC 9562 UUID v7 keys, 26-character lexicographically sortable Crockford Base32 ULIDs, compact NanoIDs, or collision-resistant CUID2 identifiers, the Run It Free UUID & Identifier Studio provides an all-in-one developer workspace. You can generate up to 100 identifiers in bulk, format outputs as UPPERCASE or lowercase, wrap them in JSON arrays, SQL INSERT statements, C# arrays, Python lists, or JavaScript arrays, and inspect any existing UUID or ULID to decode its version, variant, and embedded creation timestamp. Everything runs 100% locally in your web browser using Web Crypto APIs — ensuring zero data transmission.

How to Use UUID & Identifier Studio

1. Select Algorithm & Set Quantity: Choose between UUID v4, UUID v7, ULID, NanoID, CUID2, or Namespace UUID v5/v3. Set quantity from 1 to 100.
2. Customize Case & Formatting Variants: Toggle UPPERCASE / lowercase, or select No Hyphens, Braces '{...}', or URN format.
3. Choose Code Export Wrapper & Copy/Download: Select RAW, JSON, SQL, C#, Python, or JavaScript output. Click Copy All or Download to save the output file.
4. Inspect & Decode Existing UUIDs: Switch to the Inspector / Decoder tab and paste any UUID or ULID to reveal its embedded creation date, version, and bit structure.

Key Features

• Multi-Algorithm Identifier Support: Generate UUID v4 (random), UUID v7 (time-ordered), UUID v1 (timestamp + MAC), UUID v5 (SHA-1 namespace), UUID v3 (MD5 namespace), ULID, NanoID, and CUID2.
• UUID v7 & Time-Ordered Key Support: Create RFC 9562 compliant UUID v7 identifiers with embedded 48-bit millisecond timestamps for optimal B-Tree index locality in PostgreSQL, MySQL, and SQLite.
• Real-Time UUID & ULID Inspector / Decoder: Paste any UUID or ULID to decode its version, variant (RFC 4122 / 9562, Microsoft COM), and exact embedded creation timestamp (UTC, Local, and relative time).
• Visual Anatomy & Bit Breakdown Bar: View a color-coded structural breakdown displaying Time-Low, Time-Mid, Version, Variant, Clock Sequence, and Node/Random bits for any inspected UUID.
• Bulk Generation (1 to 100): Generate up to 100 unique identifiers at once with 1-click clipboard copy or instant file downloads (.txt, .json, .sql, .cs, .py, .js).
• Code Export Format Wrappers: Instantly format generated identifiers into Raw lines, JSON Array, SQL INSERT statements, C# string arrays, Python lists, or JS/TS array snippets.
• Custom Formatting & Formatting Variants: Toggle UPPERCASE / lowercase, Standard hyphens, No Hyphens, Braces '{...}', or URN format ('urn:uuid:...').
• Distraction-Free Zen Mode: Full-screen developer workspace with keyboard shortcut support (Esc) designed for multi-identifier inspection and session work.
• 100% Client-Side Privacy: All generation and decoding run locally in your browser via Web Crypto APIs. No keys or strings are transmitted to any server.

Benefits

• Optimizes Database B-Tree Index Performance: Using time-ordered UUID v7 or ULID for primary keys prevents database index page splitting and fragmented writes in PostgreSQL, MySQL, and Distributed SQL DBs.
• Accelerates API Mocking & Test Data Seeding: Quickly export 100 identifiers formatted directly as JSON arrays or SQL INSERT statements for seeding databases or writing unit tests.
• Decodes Legacy & Microservice Identifiers: Inspect raw database primary keys or log identifiers to instantly extract when the record was generated without writing custom bit-shift scripts.

Supported Formats & Capabilities

• UUID v4 (RFC 4122 Random)
• UUID v7 (RFC 9562 Time-Ordered)
• UUID v1 (Timestamp + Node MAC)
• UUID v5 & v3 (SHA-1 / MD5 Namespace)
• ULID (Crockford Base32 26-char Sortable)
• NanoID (URL-Friendly Custom)
• CUID2 (Collision Resistant)

Common Problems & Solutions

Why should I use UUID v7 instead of UUID v4?

UUID v4 is completely random, which causes random B-Tree page splits and index fragmentation in databases. UUID v7 includes a 48-bit millisecond timestamp at the beginning, ensuring sequential database writes while maintaining 128-bit uniqueness.

What is the difference between UUID and ULID?

UUIDs are 128-bit numbers formatted as 36-character hyphenated hex strings. ULIDs are 128-bit numbers encoded as 26 Crockford Base32 characters. Both contain timestamps and random bits, but ULIDs are shorter and case-insensitive.

How does the UUID Inspector extract timestamps?

UUID v7 embeds a 48-bit Unix timestamp in its first 6 bytes. UUID v1 embeds 100ns intervals since Oct 15, 1582. ULID embeds a 48-bit timestamp in its first 10 Base32 characters. Our inspector extracts and converts these bits to readable dates.

Pro Tips & Best Practices

• For database primary keys, prefer UUID v7 or ULID for sortability and performance.
• Use the Code Export tabs (SQL / JSON) to paste seeded test data directly into migration scripts or test suites.
• If sharing identifiers in URLs, use NanoID or ULID for shorter, URL-safe strings.

Privacy & Data Security

Zero Server Uploads — All identifier generation and UUID decoding run entirely in your web browser using Web Crypto APIs (`crypto.getRandomValues`). No generated keys or inspected strings are transmitted to any server.

Frequently Asked Questions

What is a UUID?

A Universally Unique Identifier (UUID) is a 128-bit number standardized by RFC 4122 / RFC 9562 used to uniquely identify information across computer systems without central coordination.

Is UUID v7 standardized?

Yes, UUID v7 is standardized in RFC 9562 (published by the IETF in 2024) as the official time-ordered 128-bit UUID specification.

Can I generate UUIDs offline?

Yes. Since the studio runs 100% locally in your browser using JavaScript, it works completely offline.

What code export formats are supported?

You can export generated identifiers as Raw text lines, JSON arrays, SQL INSERT statements, C# string arrays, Python lists, or JavaScript arrays.

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