This tool runs 100% inside your browser engine.
Your UUID seeds, ULID prefixes, and identifier data are processed exclusively by your local JavaScript runtime and never leave your device. No network requests are made. No analytics, logs, or telemetry capture your data. You can verify this by opening DevTools → Network tab while using the tool.
Bulk ID Engine & Analyzer
Generate clean, developer-customizable identifiers in batches. Features time-ordered UUIDv7 and Crockford ULIDs, custom prefixes, and time-freezing seed tools to back-date mock database models. Paste any past ID in the decoder below to parse versions and timestamps.
2-in-1 Identifier Inspector & Decoder
Paste any UUID (v1, v4, v7) or Crockford ULID payload into the inspection input below. The tool will parse the byte version, verify internal structures, and extract timestamps with millisecond accuracy for time-ordered identifiers.
Step-by-Step Guide
Choose an ID Format
Select the identifier type you need: UUIDv4 (random), UUIDv7 (time-ordered), or Crockford ULID. Each format has different ordering and sortability characteristics explained in the tool.
Set Count & Prefix
Enter how many IDs to generate (1-10,000) and optionally add a custom string prefix for namespace scoping (e.g. 'usr_' or 'txn_'). The prefix is prepended before the ID segment.
Generate & Inspect
Click Generate. Each ID is displayed in the results panel. For UUIDv7 and ULID formats, the timestamp decoder extracts and displays the embedded creation time.
Copy or Export
Copy individual IDs, copy all to clipboard in one click, or download the full set as a plaintext or JSON file for use in seed scripts, test fixtures, or database migrations.
Frequently Asked Questions
What is UUIDv7 and why is it preferred over UUIDv4?
UUIDv7 is a time-ordered identifier standard containing a 48-bit Unix timestamp in its most significant bits. Unlike version 4 which is completely random, UUIDv7 preserves database insertion sort order, leading to significantly lower B-tree indexing overhead and better performance.
What is the difference between UUIDv7 and ULID?
Both embed a 48-bit millisecond timestamp and offer lexicographical sorting. However, ULID uses Crockford Base32 encoding (26 characters, case-insensitive) to be more compact, while UUIDv7 maintains the standard 36-character hexadecimal RFC-9562 format.
Is any data sent to external servers?
No. The entire engine executes 100% locally inside your web browser. No input payloads, generated values, or decoded results are transmitted to PrimeByteLabs or any third-party APIs.
Can I seed sequential UUIDv7 and ULIDs in the past?
Yes. By checking 'Time Machine Seeding' and entering a custom timestamp, the ID generator freezes the baseline epoch time. Sequential records are then simulated offset by 1 millisecond per generated item.