UUID Generator

The UUID Generator produces universally unique identifiers (UUIDs) in a single click or in bulk, following the standard 128-bit format used throughout software engineering: eight hexadecimal characters, a dash, four characters, a dash, four characters, a dash, four characters, a dash, twelve characters. These identifiers are designed so that two independently generated values are, for all practical purposes, guaranteed never to collide, even across billions of records generated on different machines with no coordination between them. Developers reach for UUIDs constantly: as primary keys in distributed databases where auto-incrementing integers would create contention or reveal record counts, as session tokens, as idempotency keys for API requests, as correlation IDs threaded through microservices logs, and as unique filenames for uploaded assets so collisions never overwrite existing files. QA engineers use them to seed test fixtures with deterministic-looking but unique data, and product teams use them to tag feature flags or experiment cohorts. This tool supports the common version 4 (random) format, which is the most widely used variant because it requires no central coordination and carries no embedded timestamp or machine identifier, unlike version 1 UUIDs. A frequent question is whether UUIDs are safe to expose publicly, for example in a URL like /orders/3f2504e0-4f89-11d3-9a0c-0305e82c3301. Version 4 UUIDs are effectively unguessable thanks to 122 bits of randomness, so using them in public-facing URLs is far safer than exposing sequential integer IDs, which let an attacker enumerate every record just by incrementing a number. That said, a UUID is not a permission check — always enforce authorization server-side regardless of how unguessable the identifier looks. Practical tips: when seeding a database migration, generate the batch you need up front and store it as fixture data so tests remain deterministic across runs. When working with case-sensitive systems, note that UUIDs are conventionally lower-case but some legacy systems expect upper-case; this generator lets you choose the case and whether to include the surrounding dashes, so you can match whatever format your database driver or API contract expects. If you need to generate many at once for a bulk import or seed script, use the batch mode to produce a list you can paste directly into a CSV or SQL insert statement. Everything happens locally in your browser using the Web Crypto API's cryptographically secure random number generator — no UUID you generate here is ever sent to a server, logged, or stored anywhere outside your own machine, which makes this tool safe to use even when the resulting identifiers will back sensitive production systems. Pair it with the Hash Generator when you need a deterministic identifier derived from content rather than randomness, or the Password Generator when you need a secret rather than merely a unique label.