Random GUID Generator

Random GUID Generator — UUID v4 with Format and Case Options

The RandomStuffGenerator Random GUID Generator creates UUID v4 identifiers instantly in your browser — no server, no signup, no limits. Choose from 3 format options (Standard, No Hyphens, or Braces) and 2 case options (Lowercase or Uppercase), generate 1–10 GUIDs per click, and copy results individually or all at once.

Each GUID is a 128-bit UUID v4: 122 bits of random data with a fixed version nibble (always 4) and variant nibble (always 8, 9, a, or b). With 2¹²²possible values — approximately 5.3 × 10³⁶ — collision in any real-world application is effectively impossible.

The 3 Format Options

• 🔗 Standard (36 characters): The canonical RFC 4122 format with four hyphens grouping the hex digits as 8‑4‑4‑4‑12. Example: 550e8400-e29b-41d4-a716-446655440000. This is the default in most UUID libraries including Python's uuid.uuid4(), Node.js's crypto.randomUUID(), and PostgreSQL's gen_random_uuid().
• ➖ No Hyphens (32 characters): The same 32 hex digits with all hyphens removed. Example: 550e8400e29b41d4a716446655440000. Used when storing GUIDs in CHAR(32) columns in MySQL, in URL path segments where hyphens conflict with routing, and in legacy APIs that strip separators.
• 🔧 Braces (38 characters): The standard format wrapped in curly braces. Example: {550e8400-e29b-41d4-a716-446655440000}. The default output of C#'s Guid.NewGuid().ToString("B") and the format used throughout .NET framework internals and Windows registry GUIDs.

How to Use the Random GUID Generator

1. Choose how many GUIDs: Use the count buttons (1–10) to set how many GUIDs to generate per click.
2. Select a format: Standard, No Hyphens, or Braces — depending on what your system expects.
3. Select a case: Lowercase (RFC 4122 canonical) or Uppercase (.NET / SQL Server style).
4. Click Generate: New UUID v4 values appear instantly.
5. Copy your results: Use the per-row copy button for individual GUIDs, or Copy All to export every result as a newline-separated list.

How the GUID Generator Works

• UUID v4 algorithm: The generator fills the template xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where each x is a random hex digit (0–f), the 13th character is always 4 (version), and the 17th character is always one of 8, 9, a, or b (variant).
• Format applied after generation: The raw Standard UUID is generated first, then hyphens are stripped for No Hyphens, or braces are wrapped for the Braces format.
• Case applied last: After formatting, the entire string is optionally uppercased.
• In-browser execution: All generation happens locally using Math.random(). No data is sent to any server.

Use Cases for a Random GUID Generator

• Database primary keys: Generate GUIDs to use as primary key values when seeding a development database, creating test records, or setting up mock data fixtures.
• API testing: Use random GUIDs as resource IDs, correlation IDs, or idempotency keys in HTTP request headers during API development and testing.
• Mock data generation: Fill GUID columns in SQL scripts, JSON fixtures, or CSV import files without running a database function.
• Configuration files: Generate unique identifiers for plugin IDs, feature flags, deployment IDs, or service instance identifiers in config files.
• Documentation and examples: Use realistic-looking GUIDs in README files, API documentation, Swagger/OpenAPI specs, and code examples instead of placeholder text.
• UI/UX prototyping: Populate GUID fields in Figma, design mocks, or front-end prototypes with values that match the real data format.

GUID Format Reference

• Standard: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx — 36 characters, 32 hex + 4 hyphens. RFC 4122 canonical form.
• No Hyphens: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx — 32 characters. Used in MySQL CHAR(32), compact URLs, and legacy APIs.
• Braces: {xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx} — 38 characters. Default in C# / .NET and Windows registry entries.

UUID v4 in Major Programming Languages

• C# / .NET: Guid.NewGuid() — outputs Braces format by default with .ToString("B").
• Python: import uuid; uuid.uuid4() — outputs Standard lowercase.
• Node.js: crypto.randomUUID() (built-in since v14.17) or the uuid npm package.
• Java: UUID.randomUUID().toString() — Standard lowercase.
• Go: github.com/google/uuid — uuid.New().
• PostgreSQL: gen_random_uuid() (built-in since v13).
• SQL Server: NEWID() — outputs Uppercase Standard.
• PHP: Ramsey\Uuid\Uuid::uuid4()->toString().

Features of the Random GUID Generator

• UUID v4 generation: 122 random bits per GUID, matching RFC 4122 spec exactly.
• 3 format options:Standard, No Hyphens, and Braces to match any system's expected input.
• 2 case options: Lowercase (RFC canonical) or Uppercase (.NET / SQL Server style).
• 1–10 GUIDs per click: Bulk generate up to 10 GUIDs at once with the count selector.
• Copy individual or all: Per-row copy button plus a Copy All button for bulk export as a newline-separated list.
• Free, unlimited, no signup: Runs entirely in your browser with no data sent to any server.

Frequently Asked Questions

What is a GUID?

A GUID (Globally Unique Identifier) is a 128-bit identifier represented as 32 hex digits grouped as 8-4-4-4-12 with hyphens. The standard form looks like: 550e8400-e29b-41d4-a716-446655440000. GUID is Microsoft's name for the UUID (Universally Unique Identifier) standard defined in RFC 4122.

What is UUID v4?

UUID v4 is entirely random: 122 of the 128 bits are random data. The 13th character is always 4 (version), and the 17th is always 8, 9, a, or b (variant). It is the most widely used UUID version for general-purpose ID generation.

How unique are GUIDs — can two ever match?

UUID v4 has 2¹²² ≈ 5.3 × 10³⁶possible values. To reach a 50% chance of a collision, you would need to generate roughly 2.71 × 10¹⁸ UUIDs — about 1 billion per second for 85 years. Collisions are negligible in all real-world applications.

What are the 3 format options?

Standard adds four hyphens (36 chars). No Hyphens removes all hyphens (32 chars) for compact storage. Braces wraps the standard form in curly braces (38 chars) — the C# / .NET default. All three represent the same UUID.

Can I use these GUIDs in production?

Yes for most purposes. This tool uses Math.random(), a pseudorandom generator, which is fine for database seeding, mock data, and development. For security-critical uses where the ID must be unguessable, use a server-side cryptographic source like Node.js crypto.randomUUID().

Is the GUID generator free?

Yes — completely free. No account, no signup, no usage limits. It runs entirely in your browser with no data sent to any server.