UUID v4
Developer utility
UUID Generator
Generate one or up to 1,000 cryptographically random UUID v4 identifiers, choose a clean output format, validate pasted UUIDs, and keep every value on your device.
Local randomness
Validator
Check a UUID
Status
Version
Variant
Normalized
Batch details
Generated count
Output format
Characters
Duplicates in batch
Popular UUID presets
UUID format reference
| Format | Example | Use case |
|---|---|---|
| Standard | 550e8400-e29b-41d4-a716-446655440000 | APIs, databases, logs and configuration files |
| Compact | 550e8400e29b41d4a716446655440000 | Systems that require 32 hexadecimal characters |
| Braces | {550e8400-e29b-41d4-a716-446655440000} | Some Windows, .NET and legacy configuration formats |
| URN | urn:uuid:550e8400-e29b-41d4-a716-446655440000 | Identifiers that need an explicit UUID namespace |
UUID notes
Version 4UUID v4 uses 122 random bits, a version nibble of 4, and the RFC variant bits.
Not sequentialThese identifiers are not sortable by creation time. Use a time-ordered identifier when order matters.
Collision riskThe 122-bit random space makes accidental collisions impractical for normal applications.
Local and privateGeneration and validation run in your browser. UUIDs are not sent to this site or a third party.
UUID generator FAQ
Are these UUIDs cryptographically random?
Yes. The tool uses crypto.randomUUID() when available and crypto.getRandomValues() as a secure browser fallback.
Can I generate UUIDs in bulk?
Yes. Generate from 1 to 1,000 UUIDs and output them by line, comma, space or as a JSON array.
Which UUID forms can the validator read?
It accepts standard, compact, braces and URN forms, then reports the normalized value, version and variant. Nil and Max UUIDs are also recognized.
Can two UUID v4 values ever be the same?
A collision is mathematically possible but extraordinarily unlikely because UUID v4 provides 122 random bits.
Handy Tool Lab
How this tool is maintained
Handy Tool Lab builds and tests each tool around repeatable examples. Formula-based tools use published references when a suitable source exists; browser utilities are checked with representative inputs and output cases.