GUID Generator — Create GUIDs Online

GUID vs UUID

A GUID (globally unique identifier) is Microsoft’s name for a UUID (universally unique identifier). Both are 128-bit values written as 32 hexadecimal digits in five groups, 8-4-4-4-12. Windows tools traditionally show GUIDs in uppercase and wrapped in braces — {6F9619FF-8B86-D011-B42D-00C04FC964FF} — while most other systems use lowercase without braces. The value is the same; only the notation differs.

Using GUIDs in .NET and SQL Server

In C#, Guid.NewGuid() creates a version 4 (random) GUID and Guid.Parse("…") accepts all the formats this tool produces. In SQL Server, GUID columns use the uniqueidentifier type; choose the SQL output to get quoted values ready for an INSERT. Version 7 GUIDs start with a timestamp, so new rows land at the end of an index instead of in random places — useful for primary keys.

Are GUIDs really unique?

Version 4 GUIDs contain 122 random bits from your browser’s cryptographic random generator. You would need to create about a billion GUIDs per second for around 85 years to reach a 50% chance of a single collision, so they are safe to treat as unique.

Tools that pair well with the GUID Generator

• Hash Generator — Compute MD5 and SHA hashes of any text or file instantly, create HMAC signatures, and paste an expected checksum to verify a download.
• Password Generator — Create strong, truly random passwords or easy-to-type passphrases — with advanced rules: include or exclude words, require characters, choose allowed symbols, avoid repeats and sequences.
• Random Number Generator — Generate random numbers (with or without duplicates), pick winners from a list, shuffle names, split groups into teams, flip coins and roll dice — using your browser’s cryptographically secure randomness.
• Base64 Encode / Decode — Convert text to Base64 and back with full UTF-8 support (accents, emoji), switch to URL-safe Base64, or drop a file to get its Base64 string or data URI.