Three focused tools for working with UUID strings beyond generation. Each runs entirely client-side — paste a UUID and get results instantly, with nothing sent to a server.
UUID Validator
Paste any string and get an immediate verdict: valid or invalid, with the specific reason if it fails. The validator checks all three structural requirements defined by RFC 9562 — the 8-4-4-4-12 hexadecimal format, a version digit between 1 and 8 at position 13, and a variant digit of 8, 9, a, or b at position 17. It also recognises the nil UUID (00000000-0000-0000-0000-000000000000) and max UUID (ffffffff-ffff-ffff-ffff-ffffffffffff) as valid special-case values.
Useful when: debugging a UUID that was serialised, transmitted, or stored in a system that may have truncated or modified it; validating user-supplied UUID input; confirming that a UUID came from an RFC 9562-compliant generator.
UUID Decoder
Paste any valid UUID and see its internal structure laid out: the version number, the variant field, and — for v7 — the exact millisecond timestamp encoded in the leading 48 bits. For v1 UUIDs the decoder also extracts the 60-bit Gregorian timestamp and the node (MAC address) field. For v4 it shows the entropy breakdown.
Useful when: checking which version a UUID came from when the source code is unavailable; extracting the creation time from a v7 primary key; auditing whether legacy UUIDs in a dataset are v1 (and therefore carrying MAC addresses).
UUID Converter
Paste a UUID in any format — standard hyphenated string, 32-character hex, Base64, URL-safe Base64, or URN — and convert it to all seven representations at once, with a one-click copy button on each row. Useful when switching between systems that expect different UUID representations: a PostgreSQL uuid column, a MySQL BINARY(16) column, a JWT claim, a URL parameter, or an XML namespace.
The converter accepts all common input formats so you never need to manually strip hyphens or re-encode before pasting.
All tools
- Validate a UUID
Is it valid?
UUID ValidatorPaste any string and get an instant verdict. Checks the 8-4-4-4-12 format, the version digit (1–8), and the variant bits (8, 9, a, or b). Flags nil and max UUIDs as special cases.
- Decode a UUID
What does it contain?
UUID DecoderInspect the version and variant of any UUID. For v7, reads the 48-bit Unix millisecond timestamp. For v1, decodes the 60-bit time field and node address. For v4, shows the 122-bit entropy breakdown.
- Convert a UUID
Change the format.
UUID ConverterConvert a UUID between seven representations: standard hyphenated string, 32-char hex, uppercase hex, Base64, URL-safe Base64, URN, and 128-bit integer. Copy any format with one click.
Frequently asked questions
What does a UUID validator check?
A UUID validator checks three things: that the string matches the 8-4-4-4-12 hexadecimal format, that position 13 (the version digit) is a known version (1–8), and that position 17 (the variant digit) is 8, 9, a, or b — confirming it follows RFC 9562.
What information can you extract from a UUID?
From the UUID string alone you can read the version (digit at position 13) and variant (digit at position 17). For v1 and v7 you can also extract a timestamp — v1 embeds a 60-bit 100-nanosecond timestamp, v7 embeds a 48-bit Unix millisecond timestamp. v4 carries only random bits beyond the version and variant fields.
What formats can a UUID be represented in?
A UUID can be represented as: the standard hyphenated string (8-4-4-4-12 hex), a 32-character hex string with no hyphens, a Base64 or URL-safe Base64 string (22 characters), a URN (urn:uuid:…), or raw 16-byte binary. The hyphenated string is the canonical form defined by RFC 9562.