UUID Generator
Generate v1, v4, v5, v7, or NIL UUIDs, decode any UUID's version and timestamp, and format as braces, URN, or Base64.
UUID Generator — Generate cryptographically random version 4 UUIDs — one at a time or up to 100 in a batch. Toggle uppercase and hyphen formatting, copy the whole list or any single value with one click. UUIDs are generated with the Web Crypto API right in your browser. It also generates v1, v5, v7, and NIL UUIDs, validates and decodes any UUID you paste, and can output braces, urn:uuid:, or Base64 forms.
What is UUID Generator?
The UUID Generator is a free online tool that creates cryptographically random version 4 UUIDs, also called GUIDs, for developers, database admins, and QA engineers who need unique identifiers for primary keys, API request IDs, test fixtures, or distributed records. Generate a single UUID or batch-generate up to 100 at once, then switch the output to lowercase or UPPERCASE and toggle hyphens on or off to match your schema. Every value is produced in your browser with crypto.randomUUID() from the Web Crypto API, so this random UUID v4 generator gives you unpredictable, collision-resistant identifiers without any signup. Copy the whole newline-separated list in one click or grab any individual UUID from its own row. Beyond version 4, it also creates time-ordered version 7, timestamp-based version 1, deterministic version 5 (namespace plus name hashed with SHA-1), and the all-zero NIL UUID, plus it validates and decodes any UUID you paste — showing its version, variant, and embedded timestamp — and offers braces, urn:uuid:, and Base64 output formats.
How to use UUID Generator
- Enter how many UUIDs you want in the Count (1-100) field; the tool opens with a starter batch of 5.
- Click Generate to create a fresh batch of version 4 UUIDs.
- Choose Case, lowercase or UPPERCASE, to format the hex letters.
- Set Hyphens to With or Without to keep or strip the dashes.
- Use the copy button on the Output field to copy the entire list, or the per-row copy icon under Individual to copy a single UUID.
- Choose the UUID version — v4, v7, v1, v5, or NIL — from the Version selector; for v5 pick a namespace and enter a name.
- Paste any UUID into the Validate / Decode field to see its version, variant, and embedded timestamp.
Examples
Single lowercase UUID with hyphens, the default
Set Count to 1 and click Generate. You get one v4 UUID like 3f2504e0-4f89-41d3-9a0c-0305e82c3301; the exact value is random each time, but always in the canonical 8-4-4-4-4 hyphenated form.
Uppercase without hyphens
Switch Case to UPPERCASE and Hyphens to Without, then Generate. A value such as 3F2504E04F8941D39A0C0305E82C3301, 32 hex characters with no dashes, is produced, useful for compact keys or systems that reject hyphens.
Bulk batch of 50
Type 50 in Count and click Generate to get 50 unique UUIDs, one per line. The Generated stat shows 50 and the Version stat shows v4. Copy them all at once for seed data or test fixtures.
Frequently asked questions
- What UUID version does this generate?
- It generates version 4 (random), version 7 (time-ordered), version 1 (timestamp plus random node), version 5 (namespace and name hashed with SHA-1), and the all-zero NIL UUID. Pick the type from the Version selector; the Version stat reflects your choice and every value is built in your browser.
- How many UUIDs can I create at once?
- Between 1 and 100 per batch. The Count field accepts 1 to 100; if you enter a higher or invalid number it is clamped into the 1 to 100 range before generating.
- Can I get uppercase UUIDs or remove the hyphens?
- Yes. Use the Case toggle to switch between lowercase and UPPERCASE, and the Hyphens toggle to output values With or Without the dashes, giving you the standard 36-character or compact 32-character form.
- Can I copy just one UUID instead of the whole list?
- Yes. Each generated UUID appears on its own row under the Individual heading with its own copy icon, while the copy button on the Output field copies the entire newline-separated list.
- Does anything get uploaded to a server?
- No. Every UUID is generated entirely in your browser with the Web Crypto API. Nothing is sent to or stored on any server, so the tool works offline and your identifiers stay private.
- Can I check what version an existing UUID is?
- Yes. Paste any UUID into the Validate / Decode field and the tool reports whether it is valid, its detected version and variant, and — for version 1 and version 7 — the timestamp embedded in it, all in your browser.
- What output formats can I choose?
- Beyond lowercase or UPPERCASE and hyphens on or off, the format options let you wrap each value in braces, add the urn:uuid: prefix, or encode the 16 raw bytes as Base64.
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