UUID generator
Generate cryptographically secure Version 4 (random) and Version 1 (timestamp-based) Universally Unique Identifiers (UUIDs) locally in your browser. Choose your preferred output notation (standard hyphens, uppercase, compact 32-hex, braces, or URN), bulk generate up to 100 UUIDs at a time, download as a text file, and validate existing UUID strings with instant RFC 4122 format inspection.
Generated client-side using Web Crypto API · Zero network requests
First UUID (of 5)
45399f7c-d0c3-4adb-b0c0-aed0f855a94f
Custom count (1 - 100):
Generated UUID List (5)
1.45399f7c-d0c3-4adb-b0c0-aed0f855a94f
2.904d968b-461f-4d1c-b817-029139ae334a
3.60a1d2de-4d08-4ce7-826a-680197784e2a
4.98cb47ee-23d4-4f4c-941f-7329922979f4
5.1d2710ac-6f70-477e-8aa7-2f7f32141857
Verify or Inspect Any UUID
Example
Batch of five UUID v4 keys
Generating 5 random UUIDs in standard lowercase emits identifiers such as 'c4a760a8-dbcf-4e11-be0a-9d9e9d660000', each providing 122 bits of cryptographic entropy.
Related: JWT decoder, Hash generator, Timestamp converter, Password generator
FAQ
- What is a UUID and which version should I use?
- A Universally Unique Identifier (UUID) is a 128-bit label used to uniquely identify resources. UUID Version 4 (v4) is generated from cryptographically secure random numbers and is recommended for almost all applications, databases, and APIs. UUID Version 1 (v1) embeds a high-resolution timestamp.
- Are the UUIDs generated here truly random and collision-resistant?
- Yes. UUID v4 contains 122 bits of randomness generated by the browser's cryptographic random number generator (crypto.randomUUID / crypto.getRandomValues). The probability of a duplicate is negligible (one in 2^122).
- Are generated UUIDs uploaded or sent to a server?
- No. All UUIDs are assembled locally in your browser tab. No network calls or database logs are created.
- What output formats are supported?
- You can generate UUIDs in standard lowercase hyphenated notation (8-4-4-4-12), uppercase, compact 32-character hexadecimal without hyphens, surrounded by braces ({uuid}), or as a Uniform Resource Name (urn:uuid:...).
- Can I bulk generate UUIDs and export them?
- Yes. You can select quantities from 1 to 100 UUIDs, copy the entire list with one click, or download the batch as a plain text (.txt) file.
- How do I generate a UUID v4 programmatically?
- Use the native crypto.randomUUID() method available in all modern browsers and Node.js. If implementing manually, generate 16 random bytes, set byte[6] = (byte[6] & 0x0f) | 0x40 (version 4) and byte[8] = (byte[8] & 0x3f) | 0x80 (RFC 4122 variant), and format as 8-4-4-4-12 hex.