UUID Generator
Client-sidePopularFeaturedNewGenerate UUID v4 identifiers in bulk — uppercase and hyphenless options, fully client-side.
UUID Generator creates version-4 UUIDs in your browser with Web Crypto (when available). Generation is local — nothing is sent to a server.
Processed in your browser — data stays on your device
Key takeaways
- UUID v4 via crypto.randomUUID when available
- Bulk generate up to 100 IDs
- Optional uppercase and hyphenless output
- Fully client-side
What is a UUID v4?
UUID version 4 is a 128-bit identifier with random bits (and a fixed version/variant nibble), usually shown as 8-4-4-4-12 hexadecimal groups.
Collision risk is negligible for normal volumes. This tool does not generate time-ordered UUID v7. Use uppercase or hyphenless options when your storage format requires them.
Features
UUID v4
Cryptographically strong random UUIDs via crypto.randomUUID when available.
Bulk generate
Create up to 100 identifiers in one click for fixtures and seeds.
Format options
Toggle uppercase and remove hyphens for compact storage keys.
Copy & download
Export a newline-separated list for scripts and spreadsheets.
How it works
Choose options
Set count, uppercase, and hyphen preferences.
Generate
Click Generate to mint new UUIDs in the output panel.
Copy the list
Copy or download for use in code, SQL, or config files.
Example walkthroughs
Single UUID
Generate one v4 UUID (count is controlled in the panel).
1
Use cases
Database seeds
Mint primary keys for local fixtures and migration scripts.
Client-side IDs
Create request or correlation IDs before an API responds.
Test data
Fill forms and mocks with unique identifiers quickly.
Code snippets
UUID v4 in modern browsers
jsThis generator uses crypto.randomUUID when available.
const id = crypto.randomUUID(); // → "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"
Common errors
Count rejected
Cause: Count was outside 1–100 or not an integer.
Fix: Choose a whole number between 1 and 100 inclusive.
Need time-ordered IDs
Cause: This tool only generates UUID version 4.
Fix: Use a UUID v7 library if sortable IDs are required.
About UUID Generator
UUID Generator creates version-4 UUIDs using the Web Crypto API so you can mint identifiers for databases, tests, and APIs without a server round-trip.
Generate up to 100 IDs at once, with optional uppercase and hyphenless output.
Frequently asked questions
Which UUID version?
Version 4 (random). Time-ordered versions are not generated by this tool yet.
Are UUIDs unique?
Collision probability for v4 is astronomically low for practical volumes.
Is anything sent to a server?
No. Generation runs entirely in your browser.
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Guides & articles
How tools work on this site
Architecture overview for Tools by RS Roshi: registry-driven pages, lazy panels, SEO content, and client processors.
UUID generation notes on the RS Roshi blog
Practical write-ups around uuid generation.
Platform documentation
Shortcuts, limits, and how client-side tools work.