NanoID Generator Online
Generate compact, URL-safe, cryptographically strong unique identifiers. Smaller than UUIDs with the same collision resistance.
No account required - Start instantly
Compact IDs for Modern Applications
UUIDs are reliable but verbose. A standard UUID v4 is 36 characters long, which adds up quickly in URLs, database columns, log files, and API payloads. NanoID solves this by generating identifiers that are just 21 characters by default while providing the same level of uniqueness. The math works because NanoID uses a larger alphabet (A-Z, a-z, 0-9, underscore, and hyphen) instead of UUID's hexadecimal-only output.
Every NanoID is generated using a cryptographically secure random number generator, making them unpredictable and safe for use as access tokens, session identifiers, and public-facing resource IDs. The URL-safe alphabet means you can use them directly in URLs without encoding, in HTML attributes without escaping, and in filenames on any operating system.
Customize the length to match your security requirements. A 21-character NanoID has roughly the same collision probability as a UUID v4. Shorten it to 12 characters for low-volume use cases, or extend it to 36 characters for extreme uniqueness guarantees. The generator runs entirely in your browser with no data sent to any server.
Flexible NanoID Generation
Modern identifiers for modern apps
Compact by Default
21 characters vs 36 for UUIDs. Same uniqueness, 40% less storage and bandwidth.
URL-Safe Alphabet
Uses A-Za-z0-9_- so IDs work directly in URLs, filenames, and HTML without encoding.
Custom Length
Choose any length from 4 to 64 characters based on your collision tolerance.
Custom Alphabet
Restrict to numbers only, hex only, or define your own character set.
Batch Generation
Generate dozens of NanoIDs at once for seeding data or testing.
Cryptographically Secure
Built on the Web Crypto API. Every ID is unpredictable and safe for security use.
How to Generate NanoIDs
Compact unique IDs instantly
Set Length and Alphabet
Choose the ID length (default 21) and character set for your use case.
Generate IDs
Click generate to create one or many NanoIDs instantly.
Copy and Use
Copy individual IDs or the full list. Use them directly in your code or data.