UUID Generator
Generate UUID v4 and v1 batches
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The full guide also includes pitfalls, worked examples, snippets, FAQs, and related tools for checking results or troubleshooting.
About this tool
Generate 1–20 UUID v4 or v1 values locally after an explicit click. v4 uses Web Crypto randomness; v1 combines a timestamp with a random node ID and a clock sequence for legacy compatibility, without reading your MAC address. Choose uppercase or 32-digit compact output and copy individual IDs or a batch. Settings changes clear the old results. Values are not stored by the tool or sent to analytics. Keep database uniqueness constraints: these browser sessions do not coordinate globally. For time-oriented IDs, use the separate UUID v7 tool.
Production Snippets
Independently decode the RFC 9562 UUID v1 example with Python
python
# Source: https://www.rfc-editor.org/rfc/rfc9562.html#appendix-A.1
from datetime import datetime, timezone
from uuid import UUID
u = UUID('c232ab00-9414-11ec-b3c8-9f6bdeced846')
print(u.version) # 1
print(u.clock_seq) # 13256
print(hex(u.node)) # 0x9f6bdeced846
unix_ms = (u.time - 122192928000000000) // 10000
print(unix_ms) # 1645557742000
print(datetime.fromtimestamp(unix_ms / 1000, timezone.utc))
# 2022-02-22 19:22:22+00:00
# Published example only; generate a fresh ID for your own records.Frequently Asked Questions
Which UUID versions can I generate here?
This page generates v4 and v1, in batches of 1–20. UUID v7 is available through the separate linked UUID v7 generator.
How are UUID v4 and v1 generated?
v4 uses 122 random bits from Web Crypto with RFC version and variant bits. v1 uses a timestamp, a random node ID instead of a MAC address, and a clock sequence initialized with Web Crypto. Its page-local logical counter handles repeated milliseconds and clock rollback.
Are the UUIDs guaranteed to be unique?
No absolute guarantee is made. v4 collisions are unlikely with a working secure random source. v1 state exists only in this page instance and is not coordinated across tabs or reloads. Keep unique constraints and collision handling in production.
Can I sort UUID v1 strings by creation time?
Not reliably: the standard v1 layout puts the low timestamp field first. Decode the timestamp or sort a separate time column. Review UUID v7 for a format with a leading timestamp.
Can I remove hyphens or change case?
Yes. Compact output has 32 hexadecimal digits; standard output uses 8-4-4-4-12 groups. Case does not change the encoded bits, but some receiving APIs require the hyphenated form. Changing settings clears the old batch and the next generation creates fresh IDs.
Are generated UUIDs saved or suitable as passwords?
The tool keeps results in page memory, does not save them to browser storage, and does not send their values to analytics. Copying places them on your clipboard. UUIDs identify records; do not use them as passwords or access keys.
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