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Unique IDs

UUID Generator

Generate UUID version 4 (UUIDv4) strings instantly in your browser.
Each generated UUID is displayed immediately and can be copied with a single click.

The tool keeps a short local history of generated UUIDs, allowing you to review and reuse recent values without regenerating them.
Up to 20 entries are stored for convenience, and the history can be cleared at any time.

This generator is useful for creating temporary identifiers, testing APIs, preparing sample data, or local development tasks.
All UUID generation and history storage are handled locally in your browser.
No generated values are sent to any server, ensuring fast and privacy-safe usage.

Guide: How to use & features

  • Enter the number of UUIDs you want and click Generate to see the list.
  • Use the copy icon on each row or the bulk copy button to send them to the clipboard.
  • Generating a large batch may take a few seconds—please wait until it finishes.
  • All generation happens locally and nothing is stored after you leave the page.

Samples: Sample input & output

Generate UUID v4 values

Input

Generate 2 UUID v4 values

Output

c4f8c3f6-5f2b-4a1a-a4a8-03d52f1bb2f7
1f9a0a33-8dd9-4c4f-9c42-c8b9d4e21d45

FAQ: Frequently asked questions

  • Which UUID version is generated?

    The tool produces random-based UUID v4 values.

  • Can I generate many at once?

    You can copy or download multiple values, but generate only what you need to avoid unnecessary browser work.

  • Could the same value appear twice?

    UUID v4 is designed for a very low collision rate, so duplicates within a session are extremely unlikely.

Use cases: Common use cases

  • Numbering test data

    Generate batches of UUIDs to populate fixtures or mocks with collision-free identifiers.

  • Verifying identifier formats

    Toggle dashed and undashed forms to ensure values match what your systems expect.

  • Checking for malformed IDs

    Paste existing identifiers to confirm their validity and spot accidental truncation.

Notes: Notes & limitations

  • Work stays in your browser

    Inputs and outputs remain local. Closing the tab or clearing cache will remove any temporary state.

  • Validate critical data

    Results are helper outputs—double-check them before sending to production systems or sharing externally.

  • Large payloads depend on your device

    Very large text or files can feel slow in some browsers. Use a desktop environment for heavy workloads.
History Stores up to 20 entries

UUID Generator

UUIDs are widely used as unique identifiers for records, test data, request IDs, correlation IDs, and temporary objects. This UUID generator creates browser-side UUID values that can be copied into code, fixtures, database seeds, or debugging notes.

When it helps

  • Create test data: Generate IDs for mock records, API requests, and fixture files.
  • Trace requests: Use unique correlation IDs while debugging distributed systems.
  • Avoid manual collisions: Create identifiers that are more reliable than hand-written names or incremental test values.

Practical note

UUIDs are identifiers, not secrets. They are useful for uniqueness, but they should not be used as passwords, tokens, or access-control values unless combined with proper security design.

Articles for this tool

Introduction
2026-01-21

UUID (Universally Unique Identifier) Essentials: Types and When to Use Which

Discover what a UUID is, the differences between v1, v4, and v7, how to use them for DB primary keys, and why randomness matters from an engineer's perspective.

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A practical workflow for reading complex GitHub Actions workflow YAML by separating job dependencies from step details.

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Common pitfalls when drawing infrastructure diagrams with Mermaid

A practical guide to organizing node names, arrows, and diagram scope when building infrastructure diagrams with Mermaid in the browser.

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Generate Mermaid ER diagrams from SQL DDL to review table relationships

A practical workflow for turning CREATE TABLE statements into Mermaid ER diagrams and checking foreign keys before a schema review.

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Design notes for building JOIN queries with a Visual SQL Builder

A practical workflow for using a Visual SQL Builder to assemble SELECT, JOIN, and WHERE clauses without losing track of table relationships.

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2026-05-17

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A practical workflow for moving between CSV exports, API responses, and spreadsheet-style review without losing track of fields.

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