UUID Generator
Generate UUID v4 random identifiers. Batch 1-50, uppercase or lowercase, optional hyphens, copy single or all. 100% offline.
About this tool
Generate cryptographically random UUID v4 identifiers using your browser's Web Crypto API. Pick a count from 1 to 50, then optionally switch to uppercase and remove hyphens (32-hex form). The latest result shows in a large click-to-copy box, while a running list below keeps the last 100 generations — tap any row to copy that single UUID, or use "Copy all" to grab the full batch as a newline-separated list. The clear button resets the list. All randomness comes from crypto.getRandomValues (CSPRNG), so the UUIDs are safe for primary keys, session IDs, request IDs, and database records. No data leaves your device, no network calls, no analytics. Works fully offline.
Details
- Category
- developer
- Version
- 1.0.0
- Size
- 12 KB
- Updated
- Jun 2026
Frequently Asked Questions
What is UUID v4?
UUID v4 is the random version of the Universally Unique Identifier standard (RFC 4122). 122 of the 128 bits are random, and 6 bits are fixed (version + variant). This gives ~5.3×10³⁶ possible values — collision is practically impossible for any single app's use case.
Are these UUIDs cryptographically random?
Yes. The tool uses crypto.getRandomValues from the Web Crypto API, which is a CSPRNG. The same primitive browsers use to generate encryption keys. This is much stronger than Math.random(), which is fine for games or UI but not for security tokens.
Can I generate a batch at once?
Yes. Set "How many" between 1 and 50, then tap Generate. The latest result appears in the big box, and the full batch shows in the list below. "Copy all" grabs them as newline-separated UUIDs ready to paste into code or a database script.
What does the "no hyphens" option do?
It produces the compact 32-character hex form (for example, 5e2b8a9c0d3f4a1b8c2d6e7f9a0b1c2d) instead of the canonical 8-4-4-4-12 form. The two are equivalent identifiers — same 128 bits, same uniqueness. The compact form is friendlier in URLs, log files, and some database columns.
Is my data private?
Entirely. The list of generated UUIDs is kept only in this session — nothing is stored in localStorage, no telemetry, no server. Refresh the page and the list resets. UUIDs are safe to share (they are random and reveal nothing about you), but you stay in control of which ones you keep.