Hash & UUID Generator

What are hashes and UUIDs used for?

A hash function takes input of any size and produces a fixed-length string — the same input always produces the same hash, and even a tiny change produces a completely different one. This makes hashes useful for verifying data integrity (checksums) and, for stronger algorithms, for security-sensitive applications like password storage. A UUID (Universally Unique Identifier) is a 128-bit identifier practically guaranteed to be unique, commonly used as a database primary key or resource identifier.

When would I use this?

• Generating a checksum to verify a downloaded file wasn't corrupted.
• Creating a unique ID for a new database record or API resource during development.
• Quickly comparing whether two pieces of text are identical by comparing their hashes.

How it works

SHA-1, SHA-256, and SHA-512 use the browser's built-in Web Crypto API. MD5 (not part of Web Crypto) uses a local JavaScript implementation. UUIDs are generated with crypto.randomUUID(), which uses a cryptographically secure random source. Nothing is sent to a server.