About
Generate, inspect, and reference UUIDs in one place
AG UUID is a free toolkit for working with the unique identifiers you need every day in development and testing — no sign-up, no install.
Generate standard UUID v4, v7, v1, and NIL as well as ULID and NanoID, one at a time or up to 1,000 in bulk, and use the inspector to analyze the version, variant, and embedded timestamp of an existing UUID.
It also provides reference docs for each version and format, per-language generation code for Python, JavaScript, Go, and more, along with practical guides.
Every identifier is generated and analyzed solely with the browser's crypto.randomUUID() / getRandomValues, and no input or result is ever sent to or stored on a server.
Key features
UUID v4 — Random
A standard UUID built from 122 random bits. The most widely used version, with a collision probability that is effectively zero.
UUID v7 — Time-sorted
Stores Unix milliseconds in the first 48 bits so IDs sort by creation order. Great for database primary keys and indexes.
ULID · NanoID
Short, URL-safe alternative identifiers. ULID is time-sorted, while NanoID is a compact 21 characters.
Secure randomness
Powered by crypto.randomUUID() / getRandomValues. Generated entirely in your browser with no server upload.
Frequently asked questions
What is the difference between UUID v4 and v7?
v4 is a fully random UUID, while v7 stores a Unix millisecond timestamp in its leading bits so it can be sorted chronologically. v7 is preferable where ordering matters, such as database primary keys.
Are the values I generate or inspect sent to a server?
No. All generation and inspector analysis happens entirely with the browser's crypto API, and nothing is sent to or stored on a server.
What are ULID and NanoID, and when should I use them?
ULID is a 26-character time-sorted identifier that works well in URLs and file names, while NanoID is a 21-character URL-safe short identifier. They are alternatives to UUID when you need short links or public IDs.