Online GUID / UUID Generator
A GUID (or UUID v4) is a randomly generated 128-bit identifier used to uniquely tag database rows, API resources, session tokens, and file names without needing a central authority to hand out IDs. Generate one or up to 1,000 at once, in upper- or lowercase, with or without hyphens — generation happens locally in your browser via the Web Crypto API, so nothing is sent to a server. It helps developers create collision-resistant identifiers for records, tests, URLs, and local fixtures without a server round trip.
What is a GUID / UUID?
A GUID (Globally Unique Identifier), more commonly called a UUID (Universally Unique Identifier) outside Microsoft ecosystems, is a 128-bit value used to uniquely tag something — a database row, an API resource, a session token, a file name — without needing a central authority to hand out sequential IDs. Version 4 UUIDs, the kind this tool generates, are built from 122 random bits, which makes accidental collisions astronomically unlikely even across billions of generated values.
How to generate a GUID online
Set how many you need (up to 1,000 at once), choose whether you want uppercase or lowercase letters and whether to include the standard hyphens, then click Generate. Copy a single value with its own Copy button, or copy the entire list at once with Copy All — each value lands on its own line, ready to paste into a spreadsheet, test fixture, or script.
Common use cases
- Generating primary keys for database records that need to be unique across multiple systems or services
- Creating unique session tokens or request correlation IDs for debugging distributed systems
- Populating test fixtures or seed data with realistic-looking unique identifiers
- Naming uploaded files or temporary resources without risking a collision
Generation uses the browser's built-in Web Crypto API (crypto.randomUUID(), with a cryptographically secure fallback for older browsers) — everything happens locally, so nothing is sent to a server.
How to use GUID Generator for related tasks
Choose the desired quantity and format, generate the identifiers, and remember that random UUIDs are identifiers rather than secrets or sortable timestamps.
Related tools: Dummy Data Generator, Hash Generator.
Frequently asked questions
What is the difference between a GUID and a UUID?
There isn't one in practice — GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit identifier format that the rest of the industry calls a UUID. This tool generates UUID version 4, the randomly-generated variant, which is what people mean by "GUID" in almost all modern contexts.
How unique is a randomly generated GUID really?
UUID v4 has 122 random bits, giving roughly 5.3 undecillion possible values. The chance of two randomly generated UUIDs ever colliding is negligible enough that databases, distributed systems, and APIs rely on it as a practical guarantee of uniqueness without needing a central authority to hand out IDs.
Is it safe to generate GUIDs for production data here?
Yes — generation uses the Web Crypto API (crypto.randomUUID, with a cryptographically secure fallback for older browsers) entirely in your browser. Nothing is sent to a server, and each GUID is independent of any previous one generated.
Can I generate many GUIDs at once?
Yes, up to 1,000 in a single click, with options for uppercase/lowercase and with or without hyphens — then copy them all at once or one at a time.
What is the difference between a GUID and UUID?
In everyday software usage the terms generally describe the same 128-bit identifier format; the exact version and generation method matter more than the label.