How to use
Run a clean first pass
- Set the count (1–100), default is 1.
- Choose hyphenated format (standard 8-4-4-4-12) or compact (32 chars, no hyphens).
- Click Generate — UUIDs appear instantly. Copy individual rows or click Copy All.
UUID Generator
Generate one or many UUID v4 identifiers instantly — copy and go.
Must be 1 – 100
Format
Set a count and click Generate — UUIDs appear here instantly.
About UUID v4
UUID v4 samples 122 random bits from the browser's hardware entropy pool (crypto API). The remaining 6 bits encode the version (4) and variant (RFC 4122). Those 122 bits define the uniqueness space at roughly 5.3 × 10³⁶ possible values.
By the birthday paradox, to reach a 50% collision probability across 2¹²² values you would need to generate ~2.7 × 10¹⁸ UUIDs simultaneously. At one billion generated per second that would take ~85 years. In practice, UUID v4 is treated as globally unique.
The hyphenated format (8-4-4-4-12) is defined by RFC 4122: 32 hex characters plus 4 hyphens for 36 total. The compact form (32 chars) removes the separators only — the underlying bits are identical. Common uses: URL slugs, compact database keys, token fields.
Quick guide
Use cases, answers, and nearby tools
Compact below-tool notes that help first-run users and repeated visitors move faster without changing the main interface.
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Examples
Real jobs this page helps with
- Bulk-seed a test databaseSet count to 20, generate, click Copy All, paste into a SQL seed script.
- Compact URL tokenToggle hyphens off to get a 32-char form suitable for URL slugs or compact token fields.
FAQ
What people usually want to know
Does any data leave my browser?
No. All UUIDs are generated locally using the browser's crypto.randomUUID() API. Nothing is sent anywhere.
What is the maximum batch size?
100 UUIDs per generation. Out-of-range input shows an inline hint.
Does the hyphen toggle re-generate UUIDs?
No. It only rewrites the displayed format — the underlying bits are identical. Copy All uses the current display format.