UUID 생성기
랜덤 UUID/GUID 식별자 생성
사용 방법
값 입력
입력 필드에 숫자나 매개변수를 입력하세요.
즉시 결과 확인
입력하는 즉시 결과가 자동으로 업데이트됩니다 — 제출 버튼이 필요 없습니다.
복사 또는 저장
결과를 클립보드에 복사하거나 작업 흐름에 활용하세요.
이 도구를 사용하는 이유
100% 무료
숨겨진 비용도, 프리미엄 등급도 없습니다 — 모든 기능이 무료입니다.
설치 불필요
브라우저에서 완전히 실행됩니다. 소프트웨어를 다운로드하거나 설치할 필요가 없습니다.
프라이빗 & 안전
데이터가 기기 밖으로 나가지 않습니다. 어떤 서버에도 업로드되지 않습니다.
모바일 지원
완전 반응형 — 스마트폰, 태블릿, 데스크톱에서 사용할 수 있습니다.
UUIDs: Universally Unique Identifiers Explained
Key Takeaways
- UUIDs (v4) use 122 bits of randomness to generate identifiers that are statistically guaranteed to be unique across all systems worldwide.
- UUID v4 is the most common version — purely random with no embedded timestamp or machine information.
- All UUIDs are generated in your browser using cryptographic randomness — nothing is stored or transmitted.
Universally Unique Identifiers (UUIDs) solve the fundamental distributed systems problem of generating unique identifiers without central coordination. Whether you are building microservices, designing database schemas, or creating distributed systems, UUIDs provide a standardized way to create identifiers that will never collide, even across independent systems.
The probability of generating two identical UUID v4 values is approximately 1 in 5.3 x 10^36.
Collision Probability
Key Concepts
UUID Versions
UUID v1 uses timestamp + MAC address. V3 uses MD5 namespace hashing. V4 uses pure randomness. V5 uses SHA-1 namespace hashing. V7 (new) combines timestamp with randomness for sortability.
UUID v4 Structure
A UUID v4 follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where '4' indicates version 4 and 'y' is constrained to 8, 9, a, or b to indicate the variant. The remaining 122 bits are random.
UUID vs. Auto-Increment IDs
Auto-increment IDs are sequential and predictable, leaking information about record count and creation order. UUIDs are random and reveal nothing, making them better for public-facing identifiers.
UUID v7 — The New Standard
UUID v7 (RFC 9562) embeds a Unix timestamp in the first 48 bits, making UUIDs naturally sortable by creation time while maintaining randomness. This is ideal for database primary keys.
Pro Tips
Use UUID v7 for database primary keys — the embedded timestamp makes them naturally sortable, improving B-tree index performance.
Store UUIDs as binary (16 bytes) in databases rather than as strings (36 characters) for significant storage and performance gains.
Remove hyphens when UUIDs are used in URLs to keep them compact while maintaining readability.
Use crypto.randomUUID() in modern browsers — it is faster and more secure than JavaScript UUID libraries.
All UUIDs are generated entirely in your browser using the Web Crypto API. No generated identifiers are stored, logged, or transmitted to any server.