UUID Generator

• 100% Free

  Core tools stay free with no paywall to unlock basics.

• No Registration Required

  Open a tool and start immediately - no account needed.

• Privacy First

  We avoid unnecessary collection and keep processing local when possible.

• Browser Processing

  Most tools run in your browser so your input never needs a server round-trip.

• Fast & Secure

  HTTPS everywhere with instant, client-side results for everyday tasks.

• Mobile Friendly

  Layouts and controls are built for phones, tablets, and desktops.

• Updated Regularly

  Tools and content are improved continuously as the platform grows.

Key Features

• Cryptographically strong randomness

  Uses crypto.randomUUID() when available, falling back to crypto.getRandomValues() with the correct version and variant bits set manually - never Math.random().

• Bulk generation up to 100

  Generate anywhere from a single UUID to a full batch of 100 in one click for seeding test fixtures or sample data.

• Uppercase or lowercase formatting

  Toggle casing to match whatever convention your database, API contract, or logging system expects for hex digits.

• One-click copy and download

  Copy the full list to your clipboard or download it as a plain text file with one UUID per line.

How to Use

1. 1

   Set how many UUIDs you need

   Enter a count from 1 to 100; values outside that range are automatically clamped to a valid number.

2. 2

   Choose a letter case

   Toggle uppercase if your system or style guide expects A-F in capital letters; leave it off for the more common lowercase form.

3. 3

   Generate the batch

   Click generate to draw fresh cryptographically random values - each run produces an entirely new, independent set of identifiers.

4. 4

   Copy or export the results

   Copy everything to your clipboard for pasting into code or a spreadsheet, or download a text file for use in scripts and fixtures.

Use Cases

• Database primary and foreign keys

  Generate globally unique identifiers for records without relying on a central auto-increment counter, useful for distributed or offline-first systems.

• Test fixtures and mock data

  Seed automated tests and sample datasets with realistic-looking identifiers instead of hardcoded strings like 'id-1'.

• Correlation and trace IDs

  Create unique request or trace identifiers for logging and debugging across microservices without installing a CLI package.

• Configuration and API examples

  Quickly produce sample tokens or client IDs for documentation, Postman collections, or example .env files.

Examples

count=1, uppercase=false

3fa85f64-5717-4562-b3fc-2c963f66afa6

count=2, uppercase=true

9B1DEB4D-3B7D-4BAD-9BDD-2B0D7B3DCB6D
8F14E45F-CEEA-4B36-A2B6-0F4E9D5C7A1B

count=5, uppercase=false

Five newline-separated UUID v4 values

Benefits

• ✓Skips installing a UUID CLI package or writing a one-off script
• ✓Generates cryptographically strong values instead of predictable counters or timestamps
• ✓Produces up to 100 identifiers in a single batch for fixtures and seed data
• ✓Matches your required letter casing without a manual find-and-replace pass
• ✓Keeps generation entirely on-device so no identifiers are logged externally

Best Practices

• Default to version 4 random UUIDs unless your system specifically needs time-ordered (v1/v7) or name-based (v5) identifiers.
• Store UUIDs as native UUID/GUID column types in your database when available, rather than plain text, to save space and improve indexing.
• Treat UUIDs as unique identifiers, not as secrets - they are not designed to be unguessable authentication tokens.
• Generate a fresh batch for each dataset rather than reusing the same list of sample IDs across multiple test suites.

Common Mistakes

• Assuming UUIDs are sequential or sortable by creation time - version 4 UUIDs are fully random and carry no ordering information.
• Using a single hard-coded UUID as a shared secret or API key instead of a properly generated, rotated credential.
• Mixing uppercase and lowercase UUIDs within the same dataset, which can cause string-comparison mismatches in case-sensitive systems.

Privacy Notice

Every UUID is generated locally using your browser's Web Crypto API. No identifiers, counts, or casing preferences are ever transmitted to ToolMint's servers, which makes this safe to use even for internal or sensitive system identifiers.

About This Tool

Frequently Asked Questions

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