UUID Generator & Validator
This tool helps you generate universally unique identifiers (UUIDs) and validate existing ones. It supports both random UUIDs (version 4) and time-ordered UUIDs (version 7), along with format checks, version detection, and variant validation.
UUIDs are commonly used as identifiers in databases, APIs, and distributed systems where uniqueness matters and coordination is difficult. This tool makes it easy to create correct UUIDs and verify that incoming values conform to the standard.
How UUID Generation and Validation Works
When generating UUIDs, the tool produces identifiers that follow the RFC 4122 format. Version 4 UUIDs are generated using random values, while version 7 UUIDs incorporate a timestamp component to preserve chronological ordering.
In validation mode, the input string is checked against the UUID structure, including length, hexadecimal characters, version bits, and variant bits. This ensures that a value is not just syntactically correct, but also semantically valid as a UUID.
- Validation checks format, version, and variant only
- Uniqueness across systems cannot be guaranteed by validation
Inputs and Options Explained
The available options control how UUIDs are generated or how existing values are interpreted during validation.
- Mode — Switch between generating new UUIDs and validating an existing UUID.
- UUID version — Choose between version 4 (random) and version 7 (time-ordered).
- Count — Number of UUIDs to generate in one operation.
- Uppercase — Outputs hexadecimal characters in uppercase instead of lowercase.
- Remove hyphens — Produces compact UUIDs without dash separators.
Examples and Edge Cases
A UUID may look valid at a glance but still fail validation if its version or variant bits are incorrect. This commonly happens when identifiers are manually constructed or truncated.
Version 7 UUIDs are useful when ordering matters, such as in databases or logs. However, systems that expect only version 4 UUIDs may reject them, so compatibility should be considered.
Who Should Use This Tool
This tool is useful whenever reliable identifiers are required or when incoming IDs need to be verified.
- Developers generating IDs for databases or APIs
- Backend engineers validating user-supplied identifiers
- QA engineers testing ID handling and constraints
- Anyone learning how UUIDs are structured
Related Concepts
UUIDs are part of a broader family of identifier strategies used in software systems.
- Random identifiers — IDs generated using entropy rather than sequencing.
- Time-ordered IDs — Identifiers that preserve creation order.
- Collision resistance — The probability that two generated IDs are the same.
When UUIDs are embedded in JSON payloads, inspecting them with the JSON Formatter can make debugging easier. For generating other kinds of identifiers or fingerprints, the Hash Generator is often used alongside UUIDs.