ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character string format that combines a timestamp with random data to create identifiers that are both unique and sortable by creation time. ULIDs are an alternative to UUIDs with better sorting capabilities.

Why use ULIDs instead of UUIDs?

ULIDs offer several advantages over UUIDs: they are lexicographically sortable by generation time, they use a more compact representation (26 characters vs 36 for UUIDs), they're case-insensitive, and they avoid problematic characters like hyphens.

How do I convert a UUID to a ULID?

You can convert a UUID to a ULID using our UUID Converter tool. Simply paste your UUID into the input field and click Convert. The tool supports UUID v1, v4, v7, and any hex string, converting them losslessly to ULID format and back.

Can I decode a ULID to see its timestamp?

Yes, you can decode a ULID using our ULID Decoder tool. It will show you the timestamp in various formats (Unix timestamp, ISO string, human-readable date) and the random component in different representations.

Are ULIDs suitable for database primary keys?

Yes, ULIDs are excellent for database primary keys. They're sortable by creation time which improves database performance, they're URL-safe, and they can be generated without a central coordinator, making them ideal for distributed systems.

What is NanoID and when should I use it?

NanoID is a tiny, secure, URL-friendly unique string ID generator. It's smaller and faster than UUID and is ideal for generating short unique IDs for URLs, session tokens, or any situation where a compact random identifier is needed. Unlike ULID, NanoID is not time-sortable.

What is a Snowflake ID?

Snowflake ID is a 64-bit unique identifier format originally developed by Twitter. It encodes a timestamp, datacenter ID, machine ID, and sequence number. Snowflake IDs are sortable by time, extremely fast to generate, and widely used in distributed systems like Twitter, Discord, and Instagram.

How do I decode a JWT token?

Paste your JWT token into our JWT Decoder tool to instantly see the decoded header, payload, and signature. The tool shows all claims including expiry time (exp), issued-at (iat), and custom claims. No data is sent to any server — decoding is done entirely in your browser.

What is CUID and CUID2?

CUID (Collision-resistant Unique Identifier) is designed for horizontal scalability and sequential IDs for databases and distributed systems. CUID2 is the improved next generation with better security and randomness properties. Both are excellent alternatives to UUID for Node.js applications.

Terms of Service

Last updated: May 30, 2026

ULIDTool.net is a free, open developer tool. These terms are simple and developer-friendly.

1. Acceptance

By using ULIDTool.net, you agree to these terms. If you disagree, simply don't use the service. No account required, no sign-up, no personal data collected.

2. What You Can Do

Use the tools for any purpose — personal, commercial, open-source, enterprise
Generate and use the IDs (ULIDs, NanoIDs, etc.) in your own projects without restriction
Share the site with your team or on social media
Use the site offline (it works as a PWA)

3. What You Cannot Do

Scrape or hammer the site with automated requests at a rate that degrades service for others
Reverse-engineer or republish the site's source code as your own product without attribution
Use the service to facilitate illegal activities
Attempt to inject malicious code or exploit the service

4. No Warranties

The service is provided "as is" without warranty of any kind. ULIDTool.net is a free tool maintained in spare time. We don't guarantee uptime, accuracy, or fitness for any particular purpose. Always test IDs in your own environment before relying on them in production.

5. Limitation of Liability

To the maximum extent permitted by law, ULIDTool.net and its creator shall not be liable for any direct, indirect, incidental, or consequential damages arising from use of the service, including but not limited to loss of data, ID collisions, or service outages.

6. Availability

We reserve the right to modify, suspend, or discontinue the service at any time without notice. Since the tool runs entirely in your browser, you can also save the page locally as a backup.

7. Governing Law

These terms are governed by the laws of Vietnam. Any disputes shall be resolved in Vietnamese courts.

8. Contact

Email: [email protected]

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