UUID generator online.
Generate, validate, and bulk-export UUIDs, ULIDs, and CUID2s. Detect version, decode v7 timestamps, and download .txt or .csv — free ID generator in your browser.
Generated
10
V4 identifiers
Format
UUID v4
Cryptographically random
How to use the UUID generator online
- Select the identifier type you need, such as generate UUID v4 for random IDs or UUID v7 for time-sortable records in modern databases.
- Set a bulk count up to 100 when you need multiple values for fixtures, seed data, or migration scripts.
- Copy the generated list and paste it into your application, tests, or ETL pipeline where consistent unique IDs are required.
What is a UUID?
A UUID generator online creates globally unique identifiers that reduce collision risk across distributed systems, microservices, and offline-first clients. UUID v4 is purely random and ideal when ordering is not required, while UUID v7 includes a timestamp prefix so records are naturally sortable by creation time. Teams evaluating UUID v7 vs uuid v4 difference usually prioritize write performance in databases, index locality, and traceability for event logs. ULID is another format that stays lexicographically sortable while using compact Base32 text, which can be friendlier for URLs and copy operations. This tool runs entirely in your browser so generated IDs are never transmitted to a server, making it useful for privacy-sensitive workflows and local development environments.
Frequently asked questions
What is the difference between UUID v4 and UUID v7?+
UUID v4 is random and does not preserve creation order, which can fragment some database indexes under heavy insert load. UUID v7 includes a time component, so generated values sort by time and often improve index locality for write-heavy systems.
How to generate a UUID v4 in JavaScript?+
Use `crypto.randomUUID()` in modern browsers and Node runtimes. It uses cryptographically secure randomness and returns a standard RFC-compatible UUID string, making it a safe default for most application-level identifier requirements.
Are UUIDs truly unique?+
No identifier system can mathematically guarantee absolute uniqueness forever, but practical collision probability is extremely small. With high-entropy random generation, UUID collisions remain negligible for real-world workloads, even at very high generation rates.
When should I choose ULID instead of UUID?+
Use ULID when you want sortable IDs with shorter text that is easier to read and paste in tooling, logs, and dashboards. UUID remains more universally recognized, while ULID offers ergonomic benefits in developer workflows.