UUID Validator
UUID Validator uses a case-insensitive regular expression for 8-4-4-4-12 hexadecimal groups. The version nibble must be 1, 2, 3, 4, or 5 and the variant nibble must be 8, 9, a, or b. It does not accept braces, urn:uuid: prefixes, compact forms, UUID versions 6–8, or nil UUID, and it does not verify uniqueness, generation quality, time fields, or ownership.
Runs locally — files stay on your deviceDoes “Valid UUID” prove the identifier is unique?
No. It proves only this page's accepted textual layout and bit fields.
Syntax validation is narrower than UUID semantics
A UUID carries version and variant fields inside 128 bits. Current standards define more versions than this validator's 1–5 allowlist.
How it works
Outer whitespace is trimmed and one regular expression checks hexadecimal group lengths, a version 1–5 nibble, and an RFC variant nibble.
Key concepts
Canonical form only
Hyphens must appear in the standard positions.
Version allowlist is limited
The regex predates acceptance of v6–v8.
When to use it
- Check a canonical v1–v5 UUID string.
- Catch missing hyphens or non-hex characters.
- Validate a v4 string generated by this platform.
When not to use it
- Do not reject modern v6, v7, or v8 solely from this result.
- Do not infer database existence.
- Do not use syntax as proof of randomness or uniqueness.
Worked examples
Typical v4
- Input
550e8400-e29b-41d4-a716-446655440000- Expected output
Valid UUID
Version is 4 and variant begins a.
No hyphens
- Input
32 hex digits- Expected output
Invalid UUID
Canonical grouping is required.
Version 7
- Input
Canonical UUID with 7 version nibble- Expected output
Invalid UUID
This validator accepts only 1–5.
Common mistakes
Equating valid with existing
No lookup occurs. Correction: Check the authoritative data store.
Rejecting v7 globally
The tool's regex is limited. Correction: Use an RFC 9562-aware validator.
Including braces
Wrappers are unsupported. Correction: Pass only canonical text.
Best practices
- State the UUID version you expect.
- Use a current standard-aware validator for versions 6–8.
- Enforce uniqueness at the appropriate system boundary.
Related operations and differences
UUID Bulk Generator
Choose UUID Bulk Generator when you need to generate up to 100 secure UUIDs.; use UUID Validator specifically for uuid validate.
Base64 Decoder
Choose Base64 Decoder when you need to decode Base64 into readable text.; use UUID Validator specifically for uuid validate.
Base64 Encoder
Choose Base64 Encoder when you need to encode text as Base64 in your browser.; use UUID Validator specifically for uuid validate.
Binary to Text
Choose Binary to Text when you need to decode 8-bit binary groups into text.; use UUID Validator specifically for uuid validate.
Hex to Text
Choose Hex to Text when you need to decode hexadecimal bytes into text.; use UUID Validator specifically for uuid validate.
HTML Escape
Choose HTML Escape when you need to escape HTML-sensitive characters.; use UUID Validator specifically for uuid validate.
Limitations and privacy
- Canonical v1–v5 RFC-variant strings only.
- No nil, max, v6–v8, wrappers, compact form, semantic-field, uniqueness, provenance, or database validation.
The entered value is transformed locally in this browser and is not sent to the Toolbox server.
Copying or pasting sensitive output into another service is a separate disclosure decision.
Frequently asked questions
Are uppercase hex letters accepted?
Yes.
Is UUID v7 accepted?
No.
Are braces accepted?
No.
Does valid mean unique?
No.