UUID Validator

Validate UUID format & detect version

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About UUID Validator

A precise UUID (Universally Unique Identifier) and GUID validator that checks format compliance with RFC 4122 and RFC 9562. Auto-detects the UUID version (v1 through v7), extracts embedded timestamps from v1, v6, and v7, identifies the variant (DCE, Microsoft, NCS), and validates the structure of each field. Supports batch validation for processing multiple UUIDs at once. Includes a UUID v4 generator for creating new random UUIDs directly in the browser. Essential for developers, database administrators, and API designers.

UUID Validator Features

  • Version 1-7 detection
  • Timestamp extraction
  • Variant identification
  • UUID v4 generator
  • Batch validation
UUIDs (Universally Unique Identifiers) are 128-bit labels used across virtually every software system — from database primary keys to API correlation IDs to session tokens. While they all share the same 8-4-4-4-12 hexadecimal format, different versions encode different information: v1 and v6 embed MAC addresses and timestamps, v4 is random, and the new v7 uses Unix millisecond timestamps. This validator checks the format, detects the version and variant, and extracts embedded data when available.

How to Use the UUID Validator

Paste a UUID and get instant analysis:

  • Format check: Valid 8-4-4-4-12 hexadecimal structure
  • Version: Detected from the 13th hex digit (the version nibble)
  • Variant: Identified from the 17th hex digit (DCE 1.1, Microsoft, or NCS)
  • Timestamp: Extracted and displayed for time-based versions (v1, v6, v7)

Use the generator tab to create new UUID v4 values.

UUID Versions Explained

The UUID version is encoded in the 4 most significant bits of the 7th byte:

  • v1: Timestamp + MAC address. Can reveal when and where it was created
  • v2: DCE Security. Rarely used today
  • v3: MD5 hash of a namespace + name. Deterministic
  • v4: Random. Most popular version — 122 bits of randomness
  • v5: SHA-1 hash of a namespace + name. Deterministic
  • v6: Reordered timestamp (v1 compatible). Sortable
  • v7: Unix timestamp (ms) + random. Sortable and preferred for new designs

Common UUID Issues

Frequently caught problems:

  • Wrong length: Must be exactly 36 characters (32 hex + 4 hyphens)
  • Invalid characters: Only 0-9 and a-f (case-insensitive) are valid hex characters
  • Nil UUID: 00000000-0000-0000-0000-000000000000 is technically valid but represents 'no value'
  • Missing hyphens: Some systems store UUIDs without hyphens — the validator accepts both formats

Step-by-Step Instructions

  1. 1Paste a UUID/GUID into the input field (with or without hyphens).
  2. 2View instant validation: format check, version, and variant detection.
  3. 3For time-based versions (v1, v6, v7), see the extracted timestamp.
  4. 4Use Batch Mode to validate multiple UUIDs at once.
  5. 5Click 'Generate' to create a new random UUID v4.

UUID Validator — Frequently Asked Questions

What's the difference between a UUID and a GUID?+

UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are the same thing. 'UUID' is the term used in the RFC standards and most of the software world, while 'GUID' is Microsoft's term for the same concept. They follow the same 8-4-4-4-12 format and the same generation algorithms.

Which UUID version should I use for new projects?+

UUID v7 is recommended for most new projects (RFC 9562, 2024). It embeds a Unix millisecond timestamp, making UUIDs sortable by creation time — a major advantage for database indexing. If you need maximum compatibility with older systems, UUID v4 (random) remains the safest choice since it's universally supported.

Can two UUIDs ever be the same?+

Theoretically yes, but practically no. A UUID v4 has 122 random bits, giving 5.3 × 10³⁶ possible values. You'd need to generate about 2.7 × 10¹⁸ UUIDs (2.7 quintillion) to have a 50% chance of a single collision. At one billion UUIDs per second, that would take 86 years.

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