Need to provision thousands of database rows, seed a test environment, or mock API responses without writing a script? A bulk UUID generator produces large quantities of unique identifiers in a single session — no server round-trip, no central counter, no coordination required. Every identifier is ready to drop straight into your database, config file, or JSON payload the moment you generate it.
What Is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value defined by RFC 4122, updated by RFC 9562 (which also introduced versions 6, 7, and 8). It's represented as 36 characters arranged into five hex groups: 5d7a6a6f-0226-450f-8479-4f27821f8a56. The digit at position 13 encodes the version — "4" above confirms a random UUID v4. The browser-based uuid v4 generator produces compliant identifiers instantly using the Web Crypto API.
GUID vs UUID: GUID (Globally Unique Identifier) is Microsoft's term for the same 128-bit format. In everyday software development, GUID and UUID mean exactly the same thing — different ecosystems simply prefer different names.
When Bulk Generation Saves Time
Clicking a generator once per row stops being practical the moment your dataset has more than a handful of entries. Producing hundreds or thousands of UUIDs at once is essential for seeding a database with realistic test samples, pre-populating mock API responses, or assigning IDs before a deployment — one at a time would introduce both bottlenecks and human error.
How to Use This Bulk UUID Generator
This tool runs entirely in your browser — nothing is transmitted to a server.
Choosing Version, Quantity, and Format
Pick a version from the four buttons above — Version 4 (random) is selected by default since it's the right choice for most use cases, with Version 1, Version 7, and GUID available alongside it. Set your quantity from the preset buttons (10 up to 10,000) or enter a custom amount, then layer on any combination of format options:
- UPPERCASE — for platforms that require uppercase UUIDs
- {Braces} — wraps each value for Microsoft/COM contexts
- No Hyphens — strips hyphens for compact storage
- "Quotes" — wraps each value for pasting directly into code or JSON
- Numbered — prefixes each line with 1. 2. 3. for readability
These options combine freely, so you can produce, for example, uppercase and braced values in one batch. Pick one format and stay consistent within a project — a lowercase and an uppercase UUID string won't match in a naive string comparison, even though they represent the same 128-bit value.
Copy or Export Your Results
After generating, use Copy All to grab the entire list at once, or copy an individual value. Export the batch as TXT, CSV, or JSON — useful for importing directly into a CSV loader, a migration script, or a seed data pipeline.
UUID Version Comparison
Not all versions are created equal — use this as a quick reference before generating a batch: The uuid decoder is useful for debugging time-based UUIDs and confirming their embedded creation metadata.
| Version | Source of Uniqueness | When to Use |
|---|---|---|
| v1 | Timestamp + node/hardware address | Legacy systems needing time-ordering; exposes hardware info |
| v4 | 122 bits of cryptographic randomness | Default for most apps — use this if unsure |
| v7 | Unix millisecond timestamp + entropy | Sortable database primary keys, better index locality than v4 |
| GUID | Same as UUID v4 | Microsoft-ecosystem tooling and naming conventions |
Versions 3 and 5 aren't offered here because they're deterministic — the same namespace and name always produce the same UUID, so a batch of distinct values isn't possible without a different input for each one. Generate those individually instead.
UUID Mistakes to Avoid
- Storing UUIDs as unindexed plain strings. A UUID string is 36 characters. Without an index — or better, a native UUID column type storing 16 bytes — lookups across millions of rows become full table scans.
- Using UUID v1 when v4 is safer. Version 1 embeds the host's hardware address and a timestamp, leaking network topology information. Prefer v4 unless you specifically need the temporal component.
- Mixing uppercase and lowercase formats. An uppercase and a lowercase UUID represent the same value but won't match in a naive string comparison — pick one format and enforce it consistently, especially across microservices.
- Treating a UUID as a secret or session token. A UUID is a label, not a secret. Use purpose-built cryptographic tokens for authentication — UUIDs are for identification, not authorization.
Frequently Asked Questions
What is the difference between UUID Version 1, Version 4, and Version 7?
Version 1 derives uniqueness from a timestamp plus a hardware-derived node identifier. Version 4 is fully random, with no embedded metadata. Version 7 combines a Unix millisecond timestamp with random data, giving you both time-ordering and strong randomness.
Which UUID version should I use for bulk generation?
Version 4 is the default and the right choice for most use cases — maximum randomness, no leaked metadata. Choose Version 7 when the batch will become sortable database primary keys, or Version 1 only for compatibility with legacy systems.
Are UUID and GUID the same thing?
Yes. GUID is Microsoft's name for the identical 128-bit format defined by RFC 4122. Any UUID this tool generates, including in GUID mode, is valid for either terminology.
Can two UUIDs generated in the same batch ever collide?
For Version 4, the odds are negligible — generating a billion values per second for decades would still leave the probability of any single collision below one in a billion. Treat UUID uniqueness as statistically guaranteed for practical purposes.
Why can't I generate Version 3 or Version 5 UUIDs in bulk?
Versions 3 and 5 are deterministic: the same namespace and name always produce the same UUID. Since each one needs its own distinct input, they can't be produced as an undifferentiated batch the way random or timestamp-based versions can — generate them individually instead.
Should UUIDs be stored as strings or binary in a database?
Where your database supports a native UUID or binary type, use it — 16 bytes instead of a 36-character string means smaller indexes and faster lookups. Plain-string storage works too, but make sure the column is indexed and your format (uppercase vs. lowercase, hyphenated vs. not) is consistent across your codebase.