Loading
Preparing your generator page
We are loading content and tools so everything is ready to use.
We are loading content and tools so everything is ready to use.
Generate RFC 4122 UUID v4 values for databases, APIs, and QA — request 1–100 ids per run, four formats (Standard, Uppercase, With braces, No hyphens), optional Allow duplicate UUIDs (off by default), crypto.randomUUID when supported, validated output, and Copy to clipboard as newline-separated text.
Also try the GUID Generator, API Key Generator, and more in Utility tools.
Last updated: May 19, 2026 · Published: 2026-04-09 · Updated: 2026-05-19
Generates RFC 4122 style UUID v4 values for development, QA, and integration workflows.
Set options and click generate
A UUID generator creates version 4 universally unique identifiers — random 128-bit values formatted for databases, REST APIs, and test fixtures. Muxgen builds each id with crypto.randomUUID() when your browser supports it, validates RFC 4122 shape, applies your chosen display format, and lets you copy many ids at once.
Generation runs on click in your browser — no account and no upload of generated values to Muxgen servers.
Three steps from count to copy-ready identifier list.
Enter How many UUIDs from 1 to 100 — default 1 for a single primary key.
Choose Standard, Uppercase, With braces, or No hyphens to match your database or API parser.
Click Generate UUID(s), review results, then Copy to clipboard as a newline-separated list.
Every input and button in the live UUID generator component.
Number input id uuid-count min 1 max 100 — clamped on change, clears Copied! state.
Segmented choices: Standard (default), Uppercase, With braces, No hyphens — formatUuid runs after createUuidV4.
Checkbox default off — Set deduplication when unchecked; changes attempt limits when on.
Primary button label pluralizes when count > 1 — populates results array on click only.
Scrollable list (max-height min(420px, 55vh)) of emerald monospace cards — empty state # icon and Set options and click generate.
Ghost button joins results with \n — Copied! for 2000ms; no-op when results.length is 0.
Footer text states v4 values for development, QA, and integration workflows.
Prefers browser crypto.randomUUID(); manual randomHex builder with version 4 and variant nibbles if unavailable.
What RFC 4122 requires behind each generated value.
13th hex character is 4 — marks random UUID version in RFC 4122 layout.
17th hex character is 8, 9, a, or b — standard variant field for interoperability.
Hyphen groups after generation: 8 hex, 4, 4, 4, 12 — before optional format transforms.
Regex validates lowercase canonical form; braces stripped before test when validating.
Default lowercase hyphenated string as returned by crypto.randomUUID().
replaceAll('-', '') yields 32 contiguous hex digits for compact columns.
When to use Standard, Uppercase, braces, or hyphenless output.
Same UUID — Uppercase runs toUpperCase() on the full hyphenated string.
Wraps as {uuid} — common in COM and some Windows config samples.
32-char hex — used when parsers reject hyphens or column width is tight.
Identical mechanics — pick the page label your team and docs already use.
Unique mode dedupes formatted strings; allow duplicates may repeat for stress tests.
This tool is for quick fixtures; production services should call server-side crypto.
Need GUID terminology? Use the GUID Generator with the same format and bulk controls. Format API fixtures with the JSON Formatter before integration tests.
Generate secrets with the API Key Generator when pairing auth tokens with UUID-backed user records.
Aligned with the UUID generator component behavior.
Version and variant nibbles set correctly in both crypto and fallback paths.
Standard, Uppercase, With braces, and No hyphens without re-generating random bits.
One click produces up to one hundred newline-ready identifiers.
Optional Allow duplicate UUIDs for collision testing vs unique fixture lists.
Invalid random draws are skipped before they reach the results panel.
No sign-up; UUIDs are created locally and never uploaded to Muxgen.
Where bulk UUID generation saves engineering time.
Populate migration and fixture SQL with consistent hyphenated UUIDs.
Verify uuid columns and JSON parsers accept all four output formats.
Temporary React keys and mock row ids during component development.
Batch-generate No hyphens values for systems that store compact hex only.
Feed newline-separated lists into Playwright or Cypress data factories.
Simulate trace and session ids in logging dashboards without backend setup.
Terms used in the generator UI and RFC docs.
Universally Unique Identifier — 128-bit label, often shown as 36-character hex with hyphens.
Random version — most common for primary keys where ordering is not required.
Standard defining UUID string layout, version bits, and variant bits.
Globally Unique Identifier — Microsoft term for the same identifier family.
First hex digit of the fourth group — 8, 9, a, or b in compliant v4 output.
Checkbox that disables Set-based deduplication in bulk generation loops.
Keep identifiers consistent across environments and systems.
Generate Uppercase or braces only when Postgres, Mongo, or .NET configs require them.
Leave Allow duplicate UUIDs off so seed files do not accidentally reuse ids.
Generate dev, staging, and prod fixture sets in separate runs for easier debugging.
Paste a sample through your model validator before bulk-importing hundreds of rows.
Use database gen_random_uuid() or runtime libraries for live user records.
State whether clients send standard, braced, or hyphenless strings in OpenAPI examples.
Habits that pair with click-to-generate and newline copy.
Confirm format in your target system before generating 100 identifiers at once.
Some CSV pipelines expect 32-character columns without separator characters.
Results replace on each Generate click — copy before changing count or format.
Same tool behavior with terminology your C# README already references.
Turn on Allow duplicate UUIDs only when testing dedupe logic, not for seeds.
Pretty-print request bodies that embed uuid fields before sending to Postman.
UUID v4, bulk count 1–100, four formats, duplicates, crypto.randomUUID, GUID vs UUID, copy, and privacy.
Explore more tools in the directory.
Same v4 engine and format buttons with GUID-oriented labeling for .NET workflows.
Generate API-style secret strings for auth header and config testing.
Strong passwords for service accounts that pair with UUID primary keys.
Pretty-print API payloads that include uuid fields before integration tests.
Device identifiers with checksum rules for mobile QA alongside UUID records.
Placeholder text for UI mockups seeded with generated UUID rows.