UUID Generator & Validator

Generate cryptographically secure v4, time-ordered v7, and bulk UUIDs or validate, inspect, and extract timestamps from existing UUIDs. 100% client-side, private, and ultra-fast.

100% Client-Side Safe
• Your data is processed locally in your browser and never uploaded.

Input UUIDs (Validate / Inspect)

Generated UUIDs / Output

Conversion Settings

Mode / StatusGenerate
Count / Type-
Speed-
SPECIFICATION & CSPRNG ARCHITECTURE

UUID & GUID Generation Standard

A comprehensive reference on 128-bit Universally Unique Identifier standards, comparing pseudo-random UUID v4, time-ordered UUID v7 for database indexes, collision probabilities, and cross-platform implementation patterns.

🛡️

Zero-Knowledge Cryptographic Sandboxing

100% Client-Side • 0 Telemetry

The FreeJSONtoCSV UUID Generator & Validator executes all random byte sampling and time-ordered sequencing directly in your local browser using the Web Cryptography API (crypto.getRandomValues) and dedicated background WebWorker threads. Your generated primary keys, security tokens, and database entity IDs are never logged or transmitted over any network.

2122 Unique Keys

5.3 × 1036 combinations with zero collision risk.

CSPRNG Entropy

Hardware-backed OS randomness (never Math.random).

RFC 9562 & v7

Natural B-tree index ordering for high-speed SQL inserts.

10,000+ Bulk IDs

Instant chunked worker generation with SQL/JSON export.

Generation Lifecycle

UUID Generation Pipeline & Bit Architecture

4-Stage WebWorker
01Entropy

CSPRNG Byte Generation

Samples 16 cryptographically secure pseudo-random bytes from the browser OS entropy pool.

02Timestamp

Time Ordering (v7)

For UUID v7, injects 48-bit millisecond epoch timestamp into high bits with monotonic sequencing.

03Bit-Mask

Version & Variant Mask

Sets 4-bit version code (e.g. 0100 for v4) and 2-bit RFC 4122 variant code (10xx).

04Format

Wrapper & Serialization

Serializes 32-hex string with standard 8-4-4-4-12 hyphens, JSON arrays, SQL values, or C# GUID braces.

Practical Code Reference

Real-World UUID Manifest Patterns

Interactive Gallery

Explore how random v4, time-ordered v7, and deterministic v5 UUIDs are structured for production applications.

1. Cryptographically Secure Random UUID v4 (CSPRNG)

Preview

Purely random 122-bit entropy keys with version nibble 4 (-4xxx-) and RFC 4122 variant (-[89ab]xxx-).

entity_payload.jsonJSON Entity
{
  "apiKeyId": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
  "organization": "Acme Corp",
  "active": true
}
batch_v4.txtUUID v4 Batch
f47ac10b-58cc-4372-a567-0e02b2c3d479
c9bf9e57-1685-4c89-bafb-ff5af830be8a
710b962e-041c-4384-93e4-85ecb3701625

2. Time-Ordered UUID v7 for High-Speed Database Primary Keys

Preview

RFC 9562 time-ordered UUIDs sort chronologically by default, preventing expensive B-tree page splits during high-volume database inserts.

schema.sqlPostgreSQL Table
CREATE TABLE orders (
  id UUID PRIMARY KEY,
  customer_id UUID NOT NULL,
  amount NUMERIC(10, 2)
);
insert_v7.sqlOrdered SQL Values
INSERT INTO orders (id) VALUES
  ('018e69e4-6a8b-7f12-881b-a9f8f2b34710'),
  ('018e69e4-6a8b-7f13-94c0-2f9b1c70e341');

3. Deterministic SHA-1 Name-Based UUID v5

Preview

UUID v5 hashes a namespace (e.g. DNS namespace 6ba7b810-9dad-11d1-80b4-00c04fd430c8) with a string to generate consistent, reproducible UUIDs across distributed systems.

namespace_input.txtDNS Namespace + Name
Namespace (DNS): 6ba7b810-9dad-11d1-80b4-00c04fd430c8
Name string:     "freejsontocsv.com"
uuid_v5_output.txtReproducible UUID
c4bb47f9-2b0e-56e6-9937-97548f07b1e4
Specification Matrix

UUID Version Comparison Matrix

RFC 4122 & RFC 9562 Standards
VersionGeneration CoreSortable?Optimal Use Case
UUID v4122-bit CSPRNGNo (Random)Security nonces, unguessable API tokens, distributed entity keys.
UUID v7 (RFC 9562)48-bit Unix ms + RandYes (Chronological)Database primary keys (PostgreSQL, MySQL, SQLite, MongoDB).
UUID v160-bit 100ns + MACPartialLegacy systems requiring host node / Gregorian timestamp tracking.
UUID v5SHA-1 Namespace HashNo (Deterministic)Reproducible IDs derived from URLs, DNS domains, or usernames.
Nil / Max UUIDAll 0s / All 1sBoundaryNull initialization, boundary sentinels, placeholder defaults.
Technical Specifications

Enterprise Best Practices & Specifications

RFC 9562 & W3C Standard
🛡️

CSPRNG vs Math.random()

Standard JavaScript Math.random() is predictable and vulnerable to PRNG state recovery attacks. Our generator exclusively uses crypto.getRandomValues() backed by the operating system's cryptographic entropy source.

⚡

Database B-Tree Index Locality

Random UUID v4 values insert uniformly across the entire index tree, causing random disk I/O and cache misses. UUID v7 groups inserts sequentially by millisecond, keeping the active leaf pages hot in RAM for ultra-fast SQL performance.

⏱️

Monotonic Counter Safety

When generating thousands of UUID v7 IDs in the same millisecond, our engine increments a 12-bit sequence counter. This guarantees strict chronological sorting across concurrent distributed events without collision risks.

🔍

In-Memory Timestamp Extraction

Our UUID Validator & Inspector extracts embedded Unix timestamps directly from the 48-bit high integer of UUID v7 or the 60-bit Gregorian integer of UUID v1, rendering precise UTC timestamps down to the exact millisecond.

Developer Snippets

Cross-Language Implementation Recipes

Production Ready
Flutter / Dartuuid package
import 'package:uuid/uuid.dart';

var uuid = const Uuid();

// UUID v4 Random
String v4 = uuid.v4();

// UUID v7 Time-Ordered
String v7 = uuid.v7();
JavaScript / Node.jscrypto module
// Native v4 CSPRNG
const id = crypto.randomUUID();

// UUID v7 in Node 22+ / modern runtime
import { v7 as uuidv7 } from "uuid";
const v7Id = uuidv7();
Python 3uuid module
import uuid

# UUID v4 Random
v4_id = str(uuid.uuid4())

# UUID v5 Name-Based
v5_id = str(uuid.uuid5(uuid.NAMESPACE_DNS, "freejsontocsv.com"))
Go (Golang)google/uuid
import "github.com/google/uuid"

// Generate v4
id, _ := uuid.NewRandom()

// Generate v7 (time-ordered)
v7, _ := uuid.NewV7()
PostgreSQL 17+Native Functions
-- Generate v4
SELECT gen_random_uuid();

-- Generate v7 (PostgreSQL 17+)
SELECT uuid_generate_v7();
C# / .NET 9+System.Guid
// GUID / UUID v4
Guid v4 = Guid.NewGuid();

// UUID v7 (in .NET 9+)
Guid v7 = Guid.CreateVersion7();
FAQ

Frequently Asked Questions

Find instant, verified answers to common questions about data conversion, syntax formatting, encoding, and offline privacy.

UUIDWhat is UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 4122 and RFC 9562 used to uniquely identify entities across distributed computer networks without central coordination. Represented as 32 hexadecimal digits separated by hyphens into five groups (8-4-4-4-12, such as 550e8400-e29b-41d4-a716-446655440000), UUIDs guarantee practically zero probability of duplication. Generate yours using our online UUID generator.

UUIDWhat is a UUID?

A UUID is a standardized 16-byte label that guarantees global uniqueness. Unlike sequential database integer IDs (1, 2, 3...) which require a centralized database sequencer and are vulnerable to enumeration attacks, a UUID can be generated offline or on client devices independently with practically zero risk of collision across billions of records.

UUIDWhat does UUID stand for?

UUID stands for Universally Unique Identifier. In the Microsoft ecosystem and .NET framework, it is synonymous with GUID, which stands for Globally Unique Identifier. Both refer to the identical 128-bit RFC 4122 / RFC 9562 standard.

UUIDIs a Google Docs document ID in UUID format?

No, standard Google Docs document IDs (like the string in docs.google.com/document/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit) are not standard RFC 4122 UUIDs. Google Docs IDs are typically 44-character base64url-encoded strings representing 256-bit or 33-byte cryptographic hash keys, whereas standard UUIDs are 36 characters long with five hyphen-separated hexadecimal groups (8-4-4-4-12). However, you can generate standard UUIDs (v4 or v7) using our UUID generator to track documents and resources in your own applications.

UUIDWhat is UUID used for?

UUIDs are widely used for: 1. Database Primary Keys: Avoiding ID conflicts in distributed databases (PostgreSQL, MySQL, MongoDB, CockroachDB). 2. UUID v7 Chronological Sorting: Time-ordered keys that optimize B-tree index inserts. 3. Microservices & Tracing: Correlation IDs (X-Request-ID) tracking API requests across microservices. 4. Session & Token IDs: Unpredictable session tokens and OAuth transaction IDs. 5. File Storage: Renaming uploaded files to avoid collisions in AWS S3 or Google Cloud Storage buckets.