ToolzyLab
Generate random UUID v4 values for apps, databases, APIs, testing, and development workflows. Create one or many UUIDs instantly, format them your way, validate them, copy them, and download them — all locally in your browser.
Perfect for primary keys, identifiers, session IDs, test data, backend development, database seeding, and automation workflows. You can generate UUIDs in bulk, switch between uppercase and lowercase, wrap them in braces or quotes, change separators, validate custom UUIDs, and export the results in different formats.
Use the left side to validate or inspect a UUID. Generated output appears on the right inside a large scrollable box so the page stays clean even with huge bulk results.
Validate a UUID and inspect whether it looks like a correct UUID v4 value.
Each generated UUID can be copied individually.
Quick stuff that actually matters when using UUIDs in real projects.
A UUID is a 128-bit identifier represented in a standard hex-and-hyphen form. Choose count, case, wrappers, separator, optional prefix, hyphen removal, duplicate check, and export format according to the receiving system, then confirm version, syntax, storage type, and whether the identifier must be opaque or time ordered.
Version 4 uses random bits and is common for independent opaque identifiers. RFC 9562 also defines time-ordered versions such as v7 for systems that explicitly support them. Check what this page generates and what the database or API accepts; changing letter case or removing hyphens does not change the underlying 128-bit value.
A good generator makes accidental v4 collisions extraordinarily unlikely, yet applications should still enforce uniqueness where correctness depends on it. Batch duplicate checking only covers the current generated set. Prefixes and wrappers are presentation and may make a value incompatible with a native UUID column.
Do not place permissions in possession of a UUID alone. Some versions expose time or node-related information, and sequential use can reveal activity. Use authorization checks and cryptographically appropriate secrets for reset links, sessions, or API keys. Treat UUIDs as identifiers unless the protocol explicitly defines more.
Verify the exact version and string form against the destination contract.
Technical references: RFC 9562 UUID specification
A browser randomUUID-style generator creates version 4 UUIDs. Confirm the page output and destination requirement rather than inferring from appearance alone.
The terms are often used for the same 128-bit identifier family, though platform string or byte-order conventions can differ. Follow the receiving API or database format.
A collision is theoretically possible, while proper random v4 generation makes it extremely unlikely. Systems should still enforce uniqueness when duplicates are unacceptable.
The underlying hex digits remain, but the result is no longer the standard hyphenated text representation and some validators or native UUID types will reject it.
They can work well, but index locality, storage type, version choice, write patterns, and database support matter. Evaluate v4 versus time-ordered options under the actual workload.
No. Uniqueness does not provide authorization or guaranteed unpredictability. Use purpose-built cryptographic tokens and enforce access checks.