Generador de UUID
Genera UUIDs aleatorios de versión 4.
Acerca de UUID v4
Los identificadores UUID v4 son valores de 128 bits generados aleatoriamente formateados como 32 dígitos hexadecimales en el patrón 8-4-4-4-12. Son estadísticamente únicos — la probabilidad de colisión es insignificantemente pequeña. Usa el generador de números aleatorios criptográficos del navegador.
Preguntas frecuentes
- ¿Son criptográficamente seguros?
- Sí. Generados usando crypto.randomUUID() que usa el CSPRNG del navegador.
- ¿Cuál es la diferencia entre los formatos?
- Estándar está en minúsculas con guiones (RFC 4122). MAYÚS es lo mismo en mayúsculas. Sin guiones elimina los guiones para su uso en contextos que no los permiten.
- ¿Para qué se usan los UUIDs?
- Claves primarias de bases de datos, IDs de sesión, nombres de archivos, identificadores de sistemas distribuidos y cualquier lugar donde se necesite un ID único sin una autoridad central.
ACERCA DE ESTA HERRAMIENTA
Click once to generate a randomly generated UUID (version 4), or generate multiple at a time in bulk. A v4 UUID is 128 bits, with 122 bits coming from a random or pseudo-random source and the rest fixed to mark the version and variant per RFC 4122, giving a chance of collision so low it's treated as effectively zero even across billions of IDs. UUIDs are used as unique identifiers for database records, sessions, files, and anywhere a collision-free ID is needed without coordinating with a central counter. Generation happens locally using the browser's cryptographic random number generator, so no ID is ever sent anywhere before you use it.
CÓMO USARLO
- Click "Generate" to produce a single UUID v4.
- Set the quantity if you need a batch, then generate multiple at once.
- Choose formatting options like uppercase/lowercase or with/without hyphens, if offered.
- Copy a single UUID or copy the whole list at once.
- Paste the UUID(s) into your database seed script, code, or config file.
- Regenerate anytime — every click produces fresh, independent values.
CASOS DE USO COMUNES
- A backend developer seeds a test database with hundreds of fake primary keys before running integration tests.
- A frontend developer needs a unique "key" prop for a list of dynamically rendered React components.
- A DevOps engineer generates a unique idempotency key to include in an API request header.
- Someone designing a distributed system needs IDs that multiple services can generate independently without a shared counter.
- A QA engineer creates mock user IDs for a batch of test accounts.
CONSEJOS Y ERRORES COMUNES
- UUID v4 is random, not sequential — don't rely on generated UUIDs to sort by creation time; use v7-style timestamp-based UUIDs or a separate timestamp column if ordering matters.
- Standard UUID format is 36 characters including 4 hyphens (8-4-4-4-12 hex digits); some systems expect no hyphens, so check formatting before pasting into a strict field.
- A v4 UUID isn't cryptographically meant to be a secret — while collisions are astronomically unlikely, don't rely on a raw UUID as your only defense for something like a password reset token.
- If you need reproducible IDs for testing, generate them once and hardcode them in fixtures rather than regenerating on every test run.
MÁS PREGUNTAS
- How likely is a UUID v4 collision?
- With 122 random bits, you'd need to generate roughly 2.71 quintillion UUIDs before there's a 50% chance of a single collision, so for virtually all practical applications it's treated as impossible.
- Is a UUID the same as a GUID?
- Functionally yes — GUID is Microsoft's name for the same 128-bit identifier concept, and UUID is the more general RFC 4122 term used elsewhere.
- Why does the UUID always have specific version digits?
- In a v4 UUID, the 13th hex digit is always "4" to mark the version, and the first digit of the 4th group is always 8, 9, a, or b to mark the variant, per the RFC 4122 spec.
- Can I use a UUID as a database primary key?
- Yes, though UUIDs are larger than integers (16 bytes vs 4-8) and their randomness can hurt index locality in some databases, which is why sequential variants like UUIDv7 are gaining popularity for that use case.