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UUID Generator

Generate random UUID/GUID identifiers

Current UUID

2b43c948-0bf6-4bc8-ba86-d0a17d60d94b

Tips:

  • UUID (Universally Unique Identifier) is a 128-bit identifier
  • Generated UUIDs are version 4 (randomly generated)
  • Batch generation limit is 100

About This Tool

UUID (Universally Unique Identifier) is a standard for software construction used to generate unique identifiers. UUID consists of 32 hexadecimal digits, typically displayed in 8-4-4-4-12 format (e.g., 550e8400-e29b-41d4-a716-446655440000). This tool generates UUID v4 version, based on random numbers, making duplicates virtually impossible. Supports batch generation and format customization, all generation runs locally in your browser.

How to Use

  1. A UUID is automatically generated when the page loads, displayed in the center
  2. Click 'Generate New UUID' to get a new random UUID
  3. Check 'Uppercase' to convert letters to uppercase format
  4. Check 'No hyphens' to remove separators
  5. Set batch generation count (1-100), click 'Batch Generate'
  6. Use 'Copy' or 'Copy All' to copy UUIDs to clipboard

Common Use Cases

  • Database primary keys: As unique identifier IDs in data tables
  • Distributed systems: Generate unique IDs in systems without central nodes
  • API design: As unique identifiers for resources
  • File naming: Generate non-duplicate filenames
  • Session management: Generate user session or token IDs
  • Log tracing: Generate unique trace IDs for each request

FAQ

Q1: Can UUIDs be duplicated?

Theoretically possible, but extremely unlikely. UUID v4 has 2^122 possible values (about 5.3×10^36). Even generating a billion UUIDs per second, it would take about 100 billion years to possibly have the first duplicate. In practical applications, they can be considered unique.

Q2: What's the difference between UUID and GUID?

Essentially the same thing. UUID is the universal term, GUID (Globally Unique Identifier) is Microsoft's name, mainly used in Windows and .NET. Their format and generation methods are exactly the same.

Q3: What's the difference between UUID v4 and other versions?

UUID has 5 versions: v1 based on timestamp and MAC address; v2 based on DCE security standard; v3 and v5 based on namespace hashing (MD5/SHA1); v4 based on random numbers. V4 is the most commonly used version, completely randomly generated with no traceable information.

Q4: Can UUID be used as database primary key?

Yes, but consider: 1) UUID is long (36 characters), takes more storage space; 2) Random UUIDs are unordered, may affect B-tree index performance; 3) Not as intuitive as auto-increment IDs. Some databases have special optimizations for UUIDs. Choose based on your specific scenario.

Q5: Is UUID still valid after removing hyphens?

Valid. Hyphens are only for readability and don't affect UUID uniqueness. The 32-character format without hyphens is more convenient in some scenarios, like filenames or URL parameters.

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