Bulk UUID Generator
Generate up to 1000 UUIDs (v4) at once using crypto.randomUUID. Copy or download as a text file.
Pure browser JavaScript — uses crypto.randomUUID (RFC 4122 v4).
How to use this tool
- Set the count (1–1000).
- Toggle uppercase or brace format.
- Click Generate, then Copy all or Download.
Generate up to 1000 UUIDs (v4) at once using crypto.randomUUID. Copy or download as a text file.
How it works
A UUID (Universally Unique Identifier) version 4 is a 128-bit random value formatted as eight groups of hex digits separated by hyphens (e.g. 550e8400-e29b-41d4-a716-446655440000). The probability of two randomly generated UUIDs colliding is astronomically small, making them practical for generating unique keys without coordinating with a central authority.
This tool generates up to 1000 UUID v4 values at once using crypto.randomUUID(), the browser's cryptographically secure random number generator. You can copy all UUIDs to the clipboard or download them as a plain text file with one UUID per line.
Bulk UUID generation is useful for seeding databases with primary keys, pre-generating a batch of invitation codes, populating test fixtures with unique identifiers, or creating correlation IDs for distributed system traces.
All generation happens locally in your browser -- no UUIDs are recorded or shared with any server.
Worked example
Generate primary keys for a database seed script
- Set the quantity to the number of rows you need to insert (e.g. 200).
- Click Generate.
- Click Download to save the list as uuids.txt.
- Import the file into your seed script using a file read and assign each UUID as the id column value.
- Run the seed script to populate the database.
200 unique UUID strings saved to a text file, ready to use as database primary keys.
Common mistakes to avoid
- Generating UUIDs in your own code using Math.random() instead of crypto.randomUUID() -- Math.random() is not cryptographically secure and increases collision risk.
- Requesting far more UUIDs than needed and storing the surplus -- generate only what you need to avoid confusion later.
- Using UUID v4 as a sortable key in a database where insert order matters -- UUID v4 is random and does not sort chronologically. Consider UUID v7 or a ULID for time-ordered keys.
Key terms
- UUID v4
- A UUID where all 128 bits are randomly generated (with a few bits reserved to identify it as version 4). The most common UUID type for general-purpose unique IDs.
- crypto.randomUUID()
- A browser Web Crypto API method that generates a cryptographically secure UUID v4. Available in all modern browsers.
- CSPRNG
- Cryptographically Secure Pseudo-Random Number Generator -- the source of randomness used to produce UUID v4. Ensures values are unpredictable and collision-resistant.
Frequently asked questions
- Are these cryptographically random?
- Yes — crypto.randomUUID() uses the browser's CSPRNG, the same source used by crypto.subtle.