01
Paste the exact text
Use five hexadecimal groups in the 8-4-4-4-12 pattern. Uppercase letters work; surrounding spaces, braces and URN prefixes do not.
- Blank rows are counted separately; they are not malformed UUIDs.
Identifiers
UUID decoderInspect the fields behind an ID
One UUID per line; inspect the first valid format and the complete report.
UUID decoder
UUID input
Input is processed in this browser and is not sent to a server.
JSON report
First format-valid UUID
Time is encoded data, not proof of creation. A node field does not identify a device.
Input rules
One canonical 36-character UUID per line. Uppercase is accepted; spaces and wrappers are not removed.
Maximum 2,000 lines and 200,000 UTF-16 code units.
Enter a UUID or choose an example.
Use the UUID decoder when an API response mixes identifier versions or a log has lost its separate date column. A UUID validator can establish the shape of the text; decoding then reveals which fields the selected layout carries.
A recognized UUID version does not prove that its generator followed the standard. Treat a UUID timestamp as encoded data: it can be chosen, copied or generated by an inaccurate clock.
Why use this UUID decoder?
Distinguish clocks from random data
The UUID decoder reads v1 and v6 Gregorian ticks and v7 Unix milliseconds. A v4 identifier has no standard date to recover, so its random bytes are never presented as an event time.
Keep failed lines in the report
One malformed identifier does not erase its neighbours. Original source lines, positions, invalid values and blank rows remain in the JSON report, so you can compare it against the batch you pasted.
Check the source before the timestamp
02
Choose when results update
Automatic decoding runs 350 ms after the latest edit. Switch it off to run explicitly with the button or Ctrl/Cmd+Enter.
- Any edit makes the previous report stale and disables its exports.
03
Inspect the batch, then export
The field panel describes the first format-valid row. The JSON report covers every row, including unsupported layouts and errors outside the visible preview.
- Example and Clear always use preview, Apply and one-step Undo.
Fields you can inspect
Variant classification
Read the leading variant bits as NCS, RFC, Microsoft or reserved. Non-RFC layouts are reported without applying RFC timestamp formulas.
Version and special values
Recognize version codes 1–8 and the all-zero Nil and all-one Max identifiers. Unknown codes remain distinguishable from malformed text.
Exact time fields
v1/v6 reports preserve Gregorian ticks as decimal strings and the 100 ns remainder below a millisecond. v7 exposes its 48-bit Unix millisecond field.
Complete JSON evidence
Copy or download the whole report with original input and per-line outcomes. Display pagination does not limit the exported rows.
What the bits cannot prove
- Strict canonical form
- Each nonblank line must contain exactly 36 ASCII characters: 32 hexadecimal digits and four hyphens. No trimming or wrapper removal is performed.
- Bounded batch
- The limit is 2,000 physical lines and 200,000 UTF-16 code units. LF, CRLF and CR separate lines; one final separator does not create an extra blank row.
- No universal timestamp
- Only RFC-layout v1, v6 and v7 receive time decoding. v2 is recognized by code but its DCE fields are not decoded; v3/v4/v5/v8 have no generic recoverable time here.
- Node and random fields
- A node value and its multicast bit do not identify a computer. The decoder does not infer counters or generator strategies from v7 rand_a or rand_b.
- Structural checks only
- This page does not verify record existence, global uniqueness, authenticity or the actual creation instant. It does not generate identifiers or convert between UUID versions.
UUID decoder questions
Can an identifier reveal its date?
For RFC-layout v1, v6 and v7, yes: the UUID decoder reads the embedded clock. Other versions receive no invented date. The result is not proof of when an application record was created.
How is the variant interpreted?
The leading bits of the ninth byte identify the layout family. The tool distinguishes RFC from NCS, Microsoft and reserved variants; only the RFC layout receives version-specific time decoding.
Which UUID layouts are supported?
Canonical text is inspected for all variant families. Version codes 1–8 are recognized under the RFC variant, with Nil and Max handled separately. An unknown layout stays format-valid but unsupported.
What does the node field mean?
The 48-bit node field in v1/v6 may come from hardware or a generated value. Reading it and its multicast bit cannot establish the identity of a machine.
How do v1 and v7 clocks differ?
v1 uses a split 60-bit count of 100 ns intervals from 1582-10-15. v7 stores 48-bit milliseconds from the Unix epoch; its other fields do not reveal a universal counter scheme.
Found an unexpected result?
Open the UUID decoder
Use the UUID decoder with a known identifier, inspect its version and applicable time fields, and keep the full JSON report for comparison.