UUID Generator

Key takeaways

• UUID v4 via crypto.randomUUID when available
• Bulk generate up to 100 IDs
• Optional uppercase and hyphenless output
• Fully client-side

What is a UUID v4?

UUID version 4 is a 128-bit identifier with random bits (and a fixed version/variant nibble), usually shown as 8-4-4-4-12 hexadecimal groups.

Collision risk is negligible for normal volumes. This tool does not generate time-ordered UUID v7. Use uppercase or hyphenless options when your storage format requires them.

Features

• UUID v4

  Cryptographically strong random UUIDs via crypto.randomUUID when available.

• Bulk generate

  Create up to 100 identifiers in one click for fixtures and seeds.

• Format options

  Toggle uppercase and remove hyphens for compact storage keys.

• Copy & download

  Export a newline-separated list for scripts and spreadsheets.

How it works

1. 1

   Choose options

   Set count, uppercase, and hyphen preferences.

2. 2

   Generate

   Click Generate to mint new UUIDs in the output panel.

3. 3

   Copy the list

   Copy or download for use in code, SQL, or config files.

Example walkthroughs

• Single UUID

  Generate one v4 UUID (count is controlled in the panel).

  1

• Bulk fixture set

  Mint several IDs at once for seed data - toggle uppercase or hyphenless in the panel as needed.

  5

Use cases

• Database seeds

  Mint primary keys for local fixtures and migration scripts.

• Client-side IDs

  Create request or correlation IDs before an API responds.

• Test data

  Fill forms and mocks with unique identifiers quickly.

Code snippets

• UUID v4 in modern browsers

  js

  This generator uses crypto.randomUUID when available.

  const id = crypto.randomUUID();
  // → "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"

Common errors

• Count rejected

  Cause: Count was outside 1–100 or not an integer.

  Fix: Choose a whole number between 1 and 100 inclusive.

• Need time-ordered IDs

  Cause: This tool only generates UUID version 4.

  Fix: Use a UUID v7 library if sortable IDs are required.

About UUID Generator

UUID Generator creates version-4 UUIDs using the Web Crypto API so you can mint identifiers for databases, tests, and APIs without a server round-trip. Generate one ID or up to one hundred in a single click for fixtures and seed scripts.

Optional uppercase and hyphenless formats match storage conventions that prefer compact keys or legacy GUID casing. Collision risk for v4 is negligible at normal volumes; this tool does not generate time-ordered UUID v7 if you need sortable IDs.

Generation is fully client-side. Nothing is sent to a server, which keeps offline demos and air-gapped workflows working. Download a newline-separated list when you need to paste into SQL, CSV, or scaffolding tools.

Best practice: prefer crypto.randomUUID-backed v4 for new public IDs; do not treat UUIDs as secrets. Use Hash Generator when you need a digest of content rather than a random identifier, and JWT Decode when the string you are inspecting is a token - not a UUID.

Frequently asked questions

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