UUID Generator – Generate UUID Online (Free Tool)
Free online UUID Generator tool to generate UUID v4 (Universally Unique Identifiers) instantly. Create unique identifiers for database primary keys, session IDs, and distributed systems. Generate multiple UUIDs at once with one click. All generation happens locally using crypto API.
Example Output
Example of 3 generated UUID v4 identifiers
550e8400-e29b-41d4-a716-446655440000 6fa459ea-ee8a-3ca4-894e-db77e160355e 3c4e5a6b-7c8d-4e9f-0a1b-2c3d4e5f6a7b
What is UUID Generator?
UUID Generator creates universally unique identifiers using the v4 algorithm (random) or v1 (time-based). UUIDs are 128 bits long with a 1-in-2^122 collision chance — safe to use as database primary keys, request IDs, idempotency tokens, or anything else that needs a globally unique handle. Generation uses the browser's crypto.getRandomValues so the output is cryptographically random.
Why use this tool?
- No API keys to manage and no rate limits to monitor
- 100% free with no hidden costs or daily limits
- Works offline after the first page load
- No telemetry on the tokens, payloads, or code you paste in
- Built for developer workflows: copy-friendly output, syntax-aware highlighting where useful
How to use
- Paste the input you want to process
- Adjust any optional flags or formatting settings
- Run the conversion — everything happens locally in your browser
- Copy the output for use in your project
Examples
Generate a database primary key
Click Generate to get something like 7f3a8b2e-1c4d-4e9f-bb0a-9d8e7c6b5a4e — drop it into a CREATE statement or use as the value for a UUID column in PostgreSQL/MySQL.
Make a request ID for tracing
Generate a UUID, set it on the X-Request-Id header, and search for it in your logs to follow a single request through a distributed system.
Bulk-generate test fixtures
Generate dozens at once to seed users, orders, or any entity that needs unique IDs in a test database.
Common use cases
- Database primary keys (especially for distributed inserts)
- Idempotency keys for payment APIs (Stripe, PayPal)
- Correlation IDs for tracing requests across microservices
- Random session IDs and short-lived auth artefacts
- Filenames for uploaded files to avoid collisions
Troubleshooting
- Two UUIDs in a row look similar.
- Coincidence — v4 UUIDs are random. Inspect them character by character; the structure (8-4-4-4-12 with version digit) is fixed but the rest is random.
- Need a shorter ID.
- UUIDs are 36 chars. For shorter unique IDs, look at NanoID or short-uuid — same uniqueness with a URL-friendly alphabet.
- My database stores UUIDs as bytes and queries fail.
- PostgreSQL has a uuid type; MySQL uses BINARY(16). Make sure the column type matches and conversion is consistent in your ORM.
Frequently Asked Questions
UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. UUID v4 is randomly generated and has an extremely low probability of duplication.
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