Free UUID & ULID generator for unique identifiers.
Generate UUID and ULID values directly in your browser. Create one or many unique IDs in a single click for databases, APIs, logs, and distributed systems.
Collision-resistant IDs for real-world systems
UUIDs and ULIDs are widely used for primary keys, request IDs, trace IDs, and distributed identifiers. This tool generates them with secure randomness, entirely in your browser, with no server logging or storage.
- Generate UUID v4 and ULID values on demand.
- Create multiple IDs at once for seeding databases or fixtures.
- Choose formatting options for dashes and copy-ready output.
- Copy all IDs in one click for pasting into code or config.
Tip: Use random IDs instead of predictable auto-increment integers when you care about privacy, guessing resistance, or sharding across many nodes.
Generate UUIDs & ULIDs
IDs are generated locally using secure randomness. Use them for primary keys, request IDs, and other identifiers in your applications.
UUID v4 is purely random. ULID is random but roughly sortable by time.
Prefixes can help distinguish ID types or environments.
Dashless UUIDs can be convenient for compact storage or some APIs.
Strength: Very strong
Each ID is designed to have extremely low collision probability in typical applications. Excellent collision resistance for large-scale distributed systems.
Under the hood
- UUID v4 entropy (approx.)
- 100 bits
- ULID entropy (approx.)
- 100 bits
- IDs per batch (max)
- 5
- IDs generated (all time)
- 50K+
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How it works
Simple interface, production-ready IDs.
Behind a clean UI, this tool uses secure randomness and well-known formats to generate IDs you can safely use in production systems.
1. Choose UUID v4 or ULID
UUID v4 is fully random and widely supported. ULID is also random but sortable by time, which makes it handy for logs and database indexes.
2. Set how many you need
Generate a single ID for a config value or dozens at once to seed fixtures, test data, or local development databases.
3. Copy and paste into your stack
Copy the whole list with one click and paste it straight into code, JSON, SQL, or YAML. Each ID is unique and ready to use.
Best practices
Using UUIDs and ULIDs safely and effectively.
Unique identifiers are simple at first glance, but a few conventions can make your systems more robust and easier to reason about.
Keep IDs opaque to users
Treat IDs as internal implementation details. Don't embed sensitive information or meaning inside them—use separate fields for that.
Prefer random IDs in multi-tenant systems
Random IDs are harder to guess than incremental integers, which helps prevent simple enumeration attacks across tenants.
Use ULIDs when ordering matters
ULIDs sort roughly by time while remaining random. This can make indexes and logs easier to query compared to purely random IDs.
Don't rely on UUIDs for crypto
UUIDs and ULIDs are great identifiers but aren't a replacement for proper cryptographic keys or secrets. Use dedicated token or key generators for that.
FAQ
UUID & ULID questions, answered.
Understand the differences between UUID and ULID, and when to use each in your applications.
What's the difference between UUID and ULID?
UUID is purely random and widely supported in libraries and databases. ULID encodes both time and randomness, making it lexicographically sortable while still offering strong uniqueness.
Are IDs generated here unique enough for production?
Yes. IDs are generated using secure randomness in your browser. The chance of collisions with proper UUID or ULID usage is astronomically low for typical applications.
Do you store or log the IDs I generate?
No. All IDs are generated locally in your browser. We never see, store, or transmit them.
Should I generate IDs in my app or with this tool?
For production systems, it's best to generate IDs in your own code or database. This tool is ideal for quick tokens, local development, seeding data, and manual configuration.
UUID & ULID Generator
Local-only, no logging, no storage
Everything happens on your device. Generate, copy, and paste unique IDs without sharing them with any server.
Need secrets instead of IDs? Try our API key generator or password generator.