A UUID is really just a 128-bit number, and the familiar 36-character string is only one way to write it. This converter turns any UUID into the representations developers actually need for storage, transport, and URLs — right in your browser.
Paste a UUID above to get its binary, hexadecimal, base64, URL-safe base64, byte-array, integer, and URN forms, each with a one-click copy button.
Why convert a UUID?
Storing a UUID as text uses 36 bytes, but storing it as the underlying 16 bytes (BINARY(16) in MySQL, uuid in PostgreSQL) is more compact; index performance depends on the database and workload. The binary and byte-array outputs make it easy to see and use that raw form.
Base64 and URL-safe base64 are handy when you need a shorter, transport-friendly encoding — for example, embedding an identifier in a URL, cookie, or JSON payload without hyphens.
The formats explained
Hexadecimal removes the hyphens to give the compact 32-character form. Binary expands the 16 bytes into 128 bits. The byte array lists each of the 16 bytes in decimal, which is useful when constructing a UUID in code.
The 128-bit integer is the UUID interpreted as a single base-10 number, and the URN form (urn:uuid:…) is the IETF-registered URI representation. URL-safe base64 swaps + and / for - and _ and drops padding so the value is safe to drop straight into a URL.
Frequently asked questions
- How do I convert a UUID to binary?
- Paste the UUID above. The tool expands its 16 bytes into 128 bits and also gives you the raw byte array, which is what you store in a BINARY(16) column.
- How do I convert a UUID to base64?
- The converter encodes the UUID’s 16 bytes as base64 and as URL-safe base64 (using - and _ with no padding) so you can copy whichever your system needs.
- Should I store UUIDs as binary or text?
- Binary (16 bytes) is more compact than the 36-character text form. Index performance depends on your database and workload. Use your database’s native uuid type when available, or BINARY(16) otherwise.