Free UUID Generator — create v4 and v7 identifiers online
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value used to label information so it stays unique across systems without a central authority. Our free UUID generator creates valid version 4 (random) and version 7 (time-ordered) identifiers instantly in your browser: pick the version, choose how many you need, and copy them straight into your code, database, or config. Generation happens locally on your device — nothing is sent to a server, so it is fast, private, and works offline.
Whether you need a single primary key, a batch of test fixtures, or a correlation ID for a distributed trace, this online UUID generator produces standards-compliant identifiers in one click. It is the tool for developers who want a quick, reliable GUID without installing anything.
What is a UUID, and how is it structured?
A UUID is written as 32 hexadecimal digits in five groups separated by hyphens, for example 550e8400-e29b-41d4-a716-446655440000. Two positions encode metadata: the version (which algorithm produced it) and the variant (the layout). Because the space of possible values is astronomically large, the chance of two independently generated UUIDs colliding is effectively zero for practical purposes.
That uniqueness without coordination is why UUIDs are everywhere: database primary keys, API resource IDs, message and event identifiers, file names, and session tokens. Unlike auto-incrementing integers, a UUID can be created on any client or server before it ever reaches the database, which simplifies distributed and offline-first systems.
UUID v4 vs UUID v7 — which version should you use?
UUID v4 is fully random. It is the safe default when you simply need a unique value and do not care about ordering — think API keys, one-off identifiers, or anonymised references. Its randomness also makes it hard to guess, which is useful when the ID is exposed publicly.
UUID v7 embeds a Unix millisecond timestamp in its leading bits, so generated values sort chronologically. That time ordering makes v7 far friendlier to database indexes: rows insert near each other instead of scattering across a B-tree, which reduces index fragmentation and improves write performance at scale. Choose v7 for new primary keys where insert order matters, and v4 when unpredictability is the priority.
How to generate UUIDs
Select the UUID version (v4 or v7), set the quantity from 1 to 100, and click Generate. The identifiers appear in the output area, ready to Copy to your clipboard or Clear to start again. Generating many at once is handy for seeding a table, building a fixtures file, or populating a dropdown of test records.
Because the tool runs entirely client-side, you can regenerate as often as you like with no rate limits and no account. The output is plain text — paste it into SQL inserts, environment files, JSON payloads, or code comments without any reformatting.
Where UUIDs are used
Databases: primary and foreign keys that can be created client-side before insertion. APIs: stable, non-sequential resource identifiers that don't leak record counts. Distributed systems: correlation and trace IDs that tie together logs across services. Messaging: idempotency keys that let a consumer safely deduplicate retried events.
They also serve everyday needs: unique file and upload names, anonymous analytics identifiers, feature-flag bucketing, and one-time tokens. Anywhere you need a globally unique label that any part of your stack can mint independently, a UUID fits.
Frequently asked questions
Is this UUID generator free? Yes — unlimited use, no signup. Are the UUIDs generated privately? Yes — they are created locally in your browser and never uploaded. Can UUIDs collide? In theory yes, but the probability is so small it is ignored in practice. Which version should I pick? v7 for time-ordered database keys, v4 for random, hard-to-guess IDs. Can I generate many at once? Yes — up to 100 per batch. Do UUIDs work as database primary keys? Yes — v7 is especially index-friendly for that purpose.