UUID stands for Universally Unique Identifier. It is a 128-bit number represented as 32 hexadecimal digits in the format 8-4-4-4-12 (e.g., 550e8400-e29b-41d4-a716-446655440000). Version 4 UUIDs are generated entirely from random numbers, making collisions astronomically unlikely — you would need to generate billions of UUIDs per second for billions of years to have a meaningful chance of a duplicate.

Are these UUIDs cryptographically secure?

Yes. This tool uses your browser's crypto.randomUUID() API, which is backed by the operating system's cryptographically secure pseudorandom number generator (CSPRNG). UUIDs generated this way are suitable for security-sensitive use cases like API keys, session tokens, and database primary keys.

Can I generate multiple UUIDs at once?

Yes. Use the quantity selector to generate 1, 5, 10, 25, 50, or 100 UUIDs at once. Each UUID is independently generated. You can copy individual UUIDs or use the Copy All button to copy the entire batch.

What format options are available?

You can choose between lowercase (standard), uppercase, with hyphens (standard 8-4-4-4-12 format), or without hyphens (32 continuous hex characters). The without-hyphens format is useful for systems that store UUIDs as raw hex strings.

UUID Generator - v4 and v7 UUIDs Online in Bulk

Quantity:

Case:

Format:

Version:

UUID Generator — Free Online Tool
This tool generates UUIDs (v4 random or v7 time-sorted) using your browser's cryptographically secure random number generator. Supports bulk generation (1–100), uppercase/lowercase, and with/without hyphens formats. All generation happens in your browser — no data is ever sent to any server. Enable JavaScript to use the interactive tool.

Generated UUIDs

Click Generate to create UUIDs. All generation happens in your browser — no server round-trips.

How to Use This UUID Generator

Select quantity — Choose how many UUIDs to generate: 1, 5, 10, 25, 50, or 100 at a time.
Pick format options — Choose lowercase (standard) or uppercase, and with hyphens (550e8400-e29b-41d4-a716-446655440000) or without (550e8400e29b41d4a716446655440000).
Click Generate — Fresh UUIDs are created instantly: v4 (fully random) or v7 (time-sorted with millisecond timestamp prefix). No page reload, no server call.
Copy results — Click the Copy button next to any UUID to copy it individually, or use Copy All to copy the entire batch at once.

Why Use This UUID Generator?

Cryptographically secure

UUIDs are generated using your browser's crypto.randomUUID() API, backed by the operating system's CSPRNG. These are not pseudo-random numbers from Math.random() — they are suitable for security-sensitive use cases like API keys, session tokens, and database primary keys.

Complete privacy

All UUIDs are generated entirely in your browser. No data is ever sent to any server. This means no tracking, no logs, and no risk of your generated identifiers being intercepted or stored by a third party.

Instant, no limits

Generate as many UUIDs as you need — 1, 100, or keep clicking Regenerate. There are no rate limits, no daily quotas, and no signup required. Each generation is near-instant, even for batches of 100.

Flexible formats

Need UUIDs in a specific format? Toggle between lowercase, uppercase, with hyphens, or as 32-character raw hex strings. Useful for different database systems, API requirements, or coding conventions.

Frequently Asked Questions

What is UUID v4?

UUID version 4 is a universally unique identifier generated entirely from random numbers (122 of the 128 bits are random, with 6 bits reserved for version and variant markers). The format is xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where y is 8, 9, a, or b. The probability of generating a duplicate is so low it is effectively zero for practical purposes.

When should I use a UUID instead of an auto-increment ID?

UUIDs are ideal for distributed systems where multiple servers generate IDs independently without coordination. They also prevent ID enumeration attacks (unlike sequential IDs), work well as primary keys in distributed databases, and are useful for idempotency keys in API requests.

Is crypto.randomUUID() available in all browsers?

Yes. The crypto.randomUUID() API is supported in all modern browsers: Chrome 92+, Firefox 95+, Safari 15.4+, and Edge 92+. For older browsers, this tool falls back to crypto.getRandomValues() to build UUIDs manually.

Is this UUID generator free?

Yes, completely free. No signup, no download, no limits. Generate as many UUIDs as you need.

More Free Tools

Browse other free online tools from TryTools — all run in your browser with no signup required.

🏠 Back to All Tools ⏰ Timestamp Converter { JSON Formatter 💾 Base64 Encoder 🔗 URL Encoder 🎨 Color Converter ✍ Word Counter