UUID Generator
Generate a random UUID v4 identifier in your browser.
About this tool
UUIDs are 128-bit identifiers commonly used for database records, application objects, APIs, requests, files, and other software resources. ToolAlto provides a quick way to generate a UUID v4 when you need a fresh identifier.
How to use it
- Click Generate UUID to create a random UUID v4.
- Copy the generated UUID from the result.
- Generate another one whenever you need a new identifier.
What is UUID v4?
UUID v4 is a UUID version that uses randomly generated bits for most of its value, while specific bits identify the UUID version and variant. A typical UUID v4 looks like xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx.
When are UUIDs useful?
UUIDs are useful when identifiers need to be generated independently across applications, devices, or servers. Common examples include database IDs, API request IDs, uploaded-file identifiers, distributed systems, and temporary application objects.
UUIDs are not passwords
A UUID is an identifier, not automatically a secret or an authentication credential. Do not treat a UUID as a replacement for a password, API key, session secret, or security token unless the application's security design specifically requires and protects it.
Keep the format consistent
Most UUIDs are written as 32 hexadecimal characters separated by four hyphens. When storing UUIDs, choose a consistent database representation and keep the same format across your application, APIs, logs, and documentation.
Read the ToolAlto UUID guide →
Why use ToolAlto?
ToolAlto provides fast, free online tools for everyday tasks. We keep the experience simple, with no unnecessary signup.
Frequently asked questions
What is a UUID?
A UUID, or Universally Unique Identifier, is a 128-bit identifier commonly represented as hexadecimal text.
What is UUID v4?
UUID v4 is a UUID version based primarily on randomly generated bits, with reserved bits indicating its version and variant.
Are UUIDs guaranteed to be unique?
No identifier scheme can promise zero collisions in every circumstance. UUIDs are designed to make accidental collisions extremely unlikely when generated correctly.
Can I use a UUID as a password or API key?
A UUID is intended as an identifier and should not automatically be treated as a secret. Use purpose-built authentication and secret-generation mechanisms for security credentials.
Is the UUID generator free?
Yes. ToolAlto's UUID Generator is free to use online.