UUID/ULID/NanoID Generator
UUID/ULID/NanoID Generator: Combines 48-bit millisecond timestamp prefix with 74 bits of CSPRNG entropy from crypto.getRandomValues().
About this uuid/ulid/nanoid generator
UUID/ULID/NanoID Generator — browser-based utility.
How this tool works
Generates cryptographically secure, random RFC 4122 UUIDv4, millisecond-ordered RFC 9562 UUIDv7, Crockford Base32 monotonic ULIDs, and compact URL-safe NanoIDs using window.crypto.getRandomValues(). Also provides structural inspection and timestamp decoding for existing identifiers.
- Input Classification & Format Detection: Automatically distinguishes between second, millisecond, microsecond, and nanosecond timestamp scales, or detects hex/string representation.
- Sanitization & Range Enforcement: Verifies that timestamps fall within valid calendar epochs (-62167219200 to 253402300799) and that UUID strings conform to RFC 4122 hexadecimal grouping.
- Algorithmic Synthesis & Permutation: Generates monotonic timestamp-prefixed binary words or maps characters to standard W3C entity codepoint tables.
- Output Delivery & Verification: Displays human-readable UTC/local dates, hexadecimal representations, and verified entropy statistics.
Worked example
Scenario: Validate one canonical version-four UUID.
Sample input:
Processing: Match the canonical UUID expression and extract version and variant.
Illustrative output:
Limits and verification
Rejects timestamps resulting in dates before the year 0001 or after the year 9999. UUID parsing strictly requires 32 hexadecimal digits separated by standard 8-4-4-4-12 hyphens. Non-ASCII characters in HTML entity decoders are checked against the WHATWG Named Character Reference standard.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
- RFC 9562 (Universally Unique IDentifiers - UUIDs)
- RFC 4122 (Universally Unique IDentifier URN Namespace)
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Enter, paste, or select your input data into the UUID/ULID/NanoID Generator workspace controls.
- Review available parameter fields, units, formats, or options configured for your task.
- Click the action button or observe immediate live calculations rendered in your browser runtime.
- Inspect the resulting output and any diagnostic messages, then copy or download the result if needed.
Frequently asked questions
What does UUID Generator recognize from supplied text?+
A UUID-shaped input is checked against hexadecimal 8-4-4-4-12 groups, version 1–8 and RFC variant bits. A supplied UUIDv4 returns structured validation JSON instead of being replaced with a new random value.
What result does a supplied UUIDv4 produce?+
`550e8400-e29b-41d4-a716-446655440000` yields `valid: true` and `format: UUIDv4`. This is a deterministic validation path, not evidence about random generation quality.
Which identifier formats are limited?+
It also recognizes a 26-character Crockford-base32 ULID. Other UUID variants, malformed hyphens, arbitrary opaque IDs, and external registry lookup are outside these pattern checks.
When does it generate a new identifier?+
Text containing ULID, NanoID, v7 or time-ordered selects local generation; otherwise it uses crypto.randomUUID when available. Newly generated values are intentionally different on separate runs.