Does my UUID data leave my browser?

No. All parsing and analysis runs entirely in your browser using pure JavaScript. Nothing is sent to any server. You can use this tool completely offline after the page first loads.

What UUID versions does this tool support?

The tool auto-detects and decodes UUID versions 1, 4, 6, 7, and 8. Version 7 (RFC 9562) gets the most detailed breakdown — the 48-bit millisecond timestamp, 4-bit version field, 12-bit rand_a, 2-bit variant, and 62-bit rand_b are all labeled and color-coded in the bitfield diagram.

How does the 128-bit bitfield diagram work?

Each UUID is 128 bits. The diagram shows all 128 bits as a color-coded grid of cells arranged in 4 rows of 32 bits. Each color represents a different RFC 9562 field. Hover or tap any cell to see the field name, bit position, and value of the whole field. A proportional segment bar above the grid gives a quick visual summary of field widths.

What is bulk mode and how many UUIDs can I decode at once?

Paste multiple UUIDs (one per line) to activate bulk mode. The tool decodes up to 1,000 UUIDs and shows a timeline scatterplot of their embedded timestamps plus a monotonic-order check — useful for verifying that your system generates UUID v7s in strictly ascending order.

What does "monotonic order" mean for UUID v7?

RFC 9562 requires that UUID v7 values generated within the same millisecond must be monotonically increasing — typically by incrementing the rand_a field as a sequence counter. If your batch contains any UUID that is lexicographically smaller than the one before it, the tool flags the first violation, the index where it occurs, and both UUIDs involved.

UUID v7 ビットフィールドデコーダ

UUID v1/v4/v6/v7/v8 を128ビット RFC 9562 フィールドマップに色分けデコード。バルクペースト・タイムラインと単調順序チェック対応。

100% client-side · no upload · works offline

UUID(s) to decode

Paste a UUID above to inspect its 128-bit RFC 9562 structure

How to use

Paste one or more UUID strings (one per line) into the input box — version is detected automatically.
For a single UUID: hover any cell in the 128-bit bitfield diagram to see the field name, bit index, and full field value. The field breakdown table below it shows hex, decimal, and human-readable values.
For multiple UUIDs: check the monotonic-order badge and the timestamp timeline scatterplot to verify generation order and spot clock resets.

Related use cases

Related developer tools

よくある質問

Does my UUID data leave my browser?: No. All parsing and analysis runs entirely in your browser using pure JavaScript. Nothing is sent to any server. You can use this tool completely offline after the page first loads.
What UUID versions does this tool support?: The tool auto-detects and decodes UUID versions 1, 4, 6, 7, and 8. Version 7 (RFC 9562) gets the most detailed breakdown — the 48-bit millisecond timestamp, 4-bit version field, 12-bit rand_a, 2-bit variant, and 62-bit rand_b are all labeled and color-coded in the bitfield diagram.
How does the 128-bit bitfield diagram work?: Each UUID is 128 bits. The diagram shows all 128 bits as a color-coded grid of cells arranged in 4 rows of 32 bits. Each color represents a different RFC 9562 field. Hover or tap any cell to see the field name, bit position, and value of the whole field. A proportional segment bar above the grid gives a quick visual summary of field widths.
What is bulk mode and how many UUIDs can I decode at once?: Paste multiple UUIDs (one per line) to activate bulk mode. The tool decodes up to 1,000 UUIDs and shows a timeline scatterplot of their embedded timestamps plus a monotonic-order check — useful for verifying that your system generates UUID v7s in strictly ascending order.
What does "monotonic order" mean for UUID v7?: RFC 9562 requires that UUID v7 values generated within the same millisecond must be monotonically increasing — typically by incrementing the rand_a field as a sequence counter. If your batch contains any UUID that is lexicographically smaller than the one before it, the tool flags the first violation, the index where it occurs, and both UUIDs involved.

Last updated: 2026-05-20 By jarvisbox

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