UUID / GUID Validator
Validate Uuids (also called GUIDs) instantly. Check if your uuids are valid, detect their version, and get detailed validation feedback. Perfect for data validation, API testing, and debugging.
100% Client-Side Processing
Your uuids are validated entirely in your browser. No data is sent to any server.
You can validate multiple uuids by entering them on separate lines or separating them with commas.
Table of Contents
What is Uuid Validation?
Uuid validation is the process of checking whether a string conforms to the UUID (Universally Unique Identifier) format specified in RFC 4122. A valid Uuid must contain exactly 32 hexadecimal digits, typically displayed in five groups separated by hyphens in the format: `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`.
Validating uuids ensures that identifiers in your system are correctly formatted and can be used reliably in databases, APIs, and distributed systems. Invalid uuids can cause errors in database operations, API requests, and data processing.
Uuid Format
Uuids follow a strict format defined by RFC 4122:
- Total length: 32 hexadecimal characters (128 bits)
- Format: `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`
- Groups: 8-4-4-4-12 hexadecimal digits
- Characters: Only 0-9 and a-f (case-insensitive)
- Hyphens: Required in standard format (between groups)
- Version digit: The 13th character indicates the UUID version (1-8)
- Variant bits: The 17th character indicates the variant (must be 8, 9, a, or b)
Example Uuid Breakdown:
550e8400-e29b-41d4-a716-446655440000
│││││││││ ││││ ││││ ││││ ││││││││││││││││││││
│└─┴─┴─┴─┴─┴─┘ ││││ ││││ ││││ │└─────────────┘
│ ││││ ││││ ││││ │ Node (12 hex digits)
│ ││││ ││││ │└─┴─┴─┴─┘
│ ││││ ││││ │ Variant (4 hex digits, must start with 8, 9, a, or b)
│ ││││ │└─┴─┴─┴─┘
│ ││││ │ Version (4 hex digits, version digit at position 13)
│ │└─┴─┴─┴─┘
│ │ Time High (4 hex digits)
│ └─┴─┴─┴─┴─┴─┴─┘
│ Time Low (8 hex digits)Supported Formats
This validator accepts uuids in multiple formats:
1. Standard Format (with hyphens)
The most common format, with hyphens separating groups.
550e8400-e29b-41d4-a716-4466554400002. Without Hyphens
32 hexadecimal characters without separators.
550e8400e29b41d4a7164466554400003. GUID Format (with braces)
Microsoft GUID format with braces around the standard format.
{550e8400-e29b-41d4-a716-446655440000}4. Uppercase or Lowercase
Hex digits can be uppercase or lowercase (case-insensitive).
550E8400-E29B-41D4-A716-446655440000
550e8400-e29b-41d4-a716-446655440000The validator will normalize all formats to the standard lowercase format with hyphens for consistent output.
Use Cases
- API Development: Validate uuids in API requests and responses before processing
- Database Operations: Verify uuids before inserting or querying databases
- Data Import: Validate uuids in CSV files, JSON data, or other data sources before import
- Form Validation: Check user-entered uuids in web forms before submission
- Data Cleaning: Identify and filter out invalid uuids from datasets
- Testing & QA: Validate test data and ensure uuids are correctly formatted
- Debugging: Quickly identify malformed uuids in logs or error messages
- Data Migration: Validate uuids when migrating data between systems
- Documentation: Verify uuids in API documentation or code examples
Frequently Asked Questions
A Uuid is invalid if it doesn't match the RFC 4122 format: it must have exactly 32 hexadecimal characters (0-9, a-f), proper grouping with hyphens (in standard format), correct version and variant bits, and no invalid characters.
Yes! You can paste multiple uuids into the validator, separated by newlines or commas. The tool will validate each one individually and show detailed results for each.
Yes, the validator detects and displays the UUID version (1-8) if the version bits are set correctly. However, it doesn't validate the semantic correctness of non-v4 UUIDs (e.g., it won't verify that v1 timestamps are valid).
No, uuids are case-insensitive. Both uppercase and lowercase hexadecimal digits are valid. The validator normalizes valid uuids to lowercase for consistency.
UUID and GUID are effectively the same thing: **GUID** is Microsoft's name for the same standard, while **UUID** is the standards-based name from RFC 4122. Both refer to the same 128-bit unique identifier format. GUIDs are sometimes displayed with braces (e.g., `{550e8400-e29b-41d4-a716-446655440000}`), but the underlying format is identical.
No. All validation happens entirely in your browser using JavaScript. Your uuids never leave your device. This tool is designed with privacy as a top priority.
Yes! The validator accepts uuids in multiple formats, including without hyphens. Simply paste the 32 hexadecimal characters, and the validator will recognize and normalize it to the standard format.
The validator checks that the version digit (the 13th character) is a valid hexadecimal digit (0-f). Valid UUID versions are 1-8 according to RFC 4122. If the version is invalid or not recognized, the validator may still accept it as a valid format, but it won't display a version number.
The normalized output is the Uuid converted to the standard lowercase format with hyphens. This is useful for ensuring consistent formatting in databases and APIs. You can copy individual normalized uuids or use the "Copy Valid" button to copy all valid uuids at once.