Generate random UUID v4 identifiers instantly — one at a time or in bulk.
This free online tool generates cryptographically random, RFC 4122-compliant UUID version 4 identifiers (also called GUIDs) — one at a time or hundreds at once. Use them as database primary keys, request IDs, session tokens, or anywhere you need a unique identifier that doesn't collide.
Guid type expect)..txt file.00000000-0000-0000-0000-000000000000), often used as a sentinel "empty" value.
UUID version 4 identifiers are generated from random (or pseudo-random) bits rather than from a
timestamp or hardware address, which means they carry no information about when or where they were
created — a good default choice for most applications that just need a unique ID. This tool uses
the browser's crypto.randomUUID() / crypto.getRandomValues() API, a
cryptographically secure random number source.
Need lots of IDs as part of larger test records? The Mock Data Generator builds full JSON datasets with unique IDs, names, and emails.
All UUIDs are generated entirely in your browser using JavaScript's Web Crypto API. Nothing is sent to a server, and nothing about the generation process is logged.
A UUID is a 128-bit identifier, usually written as 32 hexadecimal digits in five hyphen-separated groups. Here's what each formatting option on this page controls.
Standard UUIDs use the format 8-4-4-4-12 hex digits separated by hyphens. Turn this off to get a compact 32-character hex string with no separators, useful for some database column formats.
UUIDs are conventionally lowercase, but some systems (older Windows APIs, certain SQL dialects) expect uppercase hex digits. This toggle switches the letters A–F to uppercase.
Wraps each UUID in { }, matching the string format .NET's Guid.ToString("B") and some COM/Windows Registry contexts use.
Generate up to 1000 UUIDs in a single click — useful for seeding test data, generating sample IDs for a fixture file, or pre-allocating identifiers for a batch import.
Generate primary keys for database records, correlation IDs for distributed tracing, or unique tokens for one-off use cases.
Quickly generate a batch of unique IDs to seed test fixtures or populate mock data for automated tests.
Generate request or trace IDs for manual testing of logging and observability pipelines.
Get a quick, collision-free identifier for a new resource, API key, or session while prototyping — no need to open a REPL.
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information, typically written as 32 hexadecimal digits in five groups separated by hyphens (e.g. xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx). "GUID" (Globally Unique Identifier) refers to the same format, mainly in Microsoft contexts.
Practically, no. UUID v4 has 122 random bits, giving roughly 5.3 x 10^36 possible values — the odds of ever generating a duplicate are astronomically small, even generating billions of UUIDs per second.
They refer to the same underlying format. "UUID" is the term used in the RFC 4122 standard and most Unix/web contexts; "GUID" is Microsoft's name for the identical concept, used throughout Windows and .NET APIs.
Yes. This tool uses the browser's crypto.randomUUID() (or crypto.getRandomValues() as a fallback), both backed by the operating system's cryptographically secure random number generator — not Math.random().
No. All UUIDs are generated entirely in your browser with JavaScript. Nothing is sent to a server, and generated values are not logged anywhere.
Built by Deepak Kumar — a developer who wanted a JSON tool that respects your privacy. All processing happens in your browser. Your data never leaves your device.