UUID Analyzer — Free Online Tool

A UUID analyzer validates a UUID string and explains what it is: version, variant, and common formatting issues. Developers use it to debug 'record not found' problems caused by hyphen/case transformations, to audit which UUID versions are used across services (v4 vs v7), and to sanity-check IDs from logs, headers, and database rows. SWEDevTools: Prism runs locally so internal identifiers do not leave your machine.

Features

Frequently Asked Questions

What is the difference between UUID v4 and v7?

v4 is random. v7 is time-ordered (timestamp-based) while remaining globally unique, which can improve index locality in databases.

Are UUID strings case-sensitive?

Hex digits are case-insensitive, but systems may compare IDs as raw text. Normalize consistently across services.

Do hyphens matter?

Not for the underlying 128-bit value, but they matter for string equality. If one component strips hyphens and another does not, lookups can fail.

Can I safely expose UUIDs publicly?

Often yes, but they are identifiers, not secrets. Use authorization and consider whether the UUID version leaks ordering/time information.

Why are UUID indexes slower than integers?

Random UUIDs can cause poor locality in B-tree indexes. Time-ordered IDs (like v7) can improve write patterns depending on the database.

Is ULID the same as UUID?

No. ULID uses a different textual encoding and ordering scheme. Do not assume interchangeability.

What does 'variant' mean?

Variant describes certain fixed bits that indicate the UUID layout rules. Most modern UUIDs use the RFC 4122 variant.

How should I generate UUIDs safely?

Use a well-tested library for your language/runtime. Avoid custom RNG implementations and ensure strong randomness when required.

What happened to smalldev.tools?

smalldev.tools is no longer available. Prism by SWEDevTools offers the same developer tools and more, with offline support, pipeline chaining, and completely free usage — no signup required.

Is Prism a good alternative to uuidgenerator.net?

Yes. Prism generates and analyzes UUIDs entirely offline with bulk generation, pipeline chaining to other tools, and complete privacy. No data ever touches a server.