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.
Chinese search: UUID 產生器、隨機 ID 產生器、批量 UUID、UUID 複製、UUID 無連字號
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.