Free UUID Generator Online
Generate UUID v4 (random) or v1 (timestamp) GUIDs in bulk (up to 100 at once). Copy, download, or pick uppercase, no-hyphens, and bracket formats. 100% in your browser.
About UUIDs
- • UUID v4: Randomly generated, most commonly used. 122 random bits ensure uniqueness.
- • UUID v1: Generated using timestamp and MAC address. Sortable and time-based.
- • Format: Standard format is 8-4-4-4-12 hexadecimal digits (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
- • Use cases: Database primary keys, session IDs, transaction IDs, unique filenames
Security note: UUIDs are not cryptographically secure. Don't use them for security tokens or passwords.
How to Use
- 1Select your preferred UUID version (v4 for random, v1 for timestamp-based)
- 2Choose the output format (default, uppercase, no hyphens, or with brackets)
- 3Set the number of UUIDs you want to generate (1-100)
- 4Click 'Generate UUIDs' to create your unique identifiers
- 5Copy individual UUIDs or all at once using the copy buttons
- 6Download the UUIDs as a text file if needed
UUID Best Practices
- •Use UUID v4 for most general purposes - it's random and universally unique
- •Use UUID v1 when you need sortable, time-based identifiers
- •UUIDs make excellent database primary keys with no collision risk
- •Store UUIDs in binary format in databases to save space (16 bytes vs 36 characters)
- •Consider using UUIDs for distributed systems where auto-increment IDs won't work
- •UUIDs are case-insensitive - both uppercase and lowercase are valid
- •Never use UUIDs for security purposes or as secret tokens
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Frequently Asked Questions
What is a UUID generator?
A UUID generator creates Universally Unique Identifiers (also called GUIDs): 128-bit IDs used as database keys, session tokens, and distributed-system IDs. This free online tool generates UUID v4 (random) or v1 (timestamp-based) in your browser.
What's the difference between UUID v1 and v4?
UUID v4 is fully random, best for privacy and general use. UUID v1 embeds a timestamp and node ID, so IDs are sortable by creation time but slightly more predictable. Most developers choose v4.
Can I generate UUIDs in bulk?
Yes. Generate up to 100 UUIDs at once, then copy individually, copy all, or download as a .txt file. Supports default, uppercase, no-hyphens, and bracketed Microsoft GUID formats.
Are online UUID generators safe for production?
This tool uses JavaScript's crypto-quality randomness in your browser. Nothing is sent to a server. For security-sensitive tokens (API keys, passwords), use a dedicated secrets manager instead of UUIDs.
Can I use these UUIDs as database primary keys?
Absolutely. UUIDs are standard primary keys in PostgreSQL, MySQL, MongoDB, and distributed systems where auto-increment IDs would collide across nodes.