UUID v4 Generator

How to use

1. Drag the slider to choose how many UUIDs you need (up to 500).
2. Optionally enable uppercase or no-hyphen formats.
3. Click Generate, then copy individual values, copy all, or download as a text file.

Use cases

1. Use case: Create database keys Generate a batch of UUID v4 values to use as primary keys for seeding a table.

2. Use case: Generate API identifiers Produce unique IDs for orders, sessions or files with the no-hyphen option for cleaner keys.

Practical tips

Version 4 UUIDs get their uniqueness from randomness, not from a registry, so generating them locally is exactly as valid as any other source. Keep them lowercase if your database is case-sensitive about string keys; storing the same UUID in two cases creates two-looking-one values. Treat UUIDs as identifiers, never as secrets — anyone who sees one can use it. Generate in bulk for test fixtures rather than reusing one sample value. Like every tool on this site, the Uuid Generator runs entirely in your browser: the data you enter never leaves your device, nothing is uploaded to a server, and the tool keeps working if your connection drops.

Common mistakes

UUID misuse usually comes from treating identifiers as something they are not:

• Treating a UUID as a secret — it is an identifier, not a credential; anyone who obtains one can use it.
• Reusing one sample UUID across all test fixtures, which masks bugs that only surface when identifiers actually differ.
• Storing UUIDs in mixed case in a case-sensitive database column, creating two values that look identical but never match in queries.
• Generating them one at a time by hand for bulk test data instead of using the batch mode.

Frequently asked questions