How to use UUID Generator
This UUID tool now combines generation and inspection in one workflow. You can generate UUID v1, UUID v4, UUID v7, ULID, and NanoID values in bulk, choose output formatting for UUID variants, and decode embedded timestamps from UUID v1/v7 or ULID inputs. Everything runs entirely in your browser, so generated identifiers and decoded values never leave your device while you validate format, ordering behavior, and timestamp metadata.
- Choose the generator mode: UUID v1, UUID v4, UUID v7, ULID, or NanoID depending on your system requirements.
- Set how many identifiers to create in bulk, then adjust UUID format or NanoID length when needed.
- Click Generate to produce the list, then copy one identifier or copy the full batch for scripts and seed data.
- Paste a UUID or ULID into the decoder panel and run Decode to inspect embedded timestamp, version, and variant details.
- Use decoded timestamps to troubleshoot ordering issues, replay windows, or data migration timelines.
Your data never leaves your device — 100% private processing.
Choosing between UUID v7, ULID, and NanoID
UUID v7 is now the preferred modern UUID for many databases because its leading timestamp bits keep inserts mostly chronological, reducing index churn compared with UUID v4. ULID offers similar time-order behavior in a shorter, case-insensitive Base32 string that is easier for humans to read. NanoID is ideal when you need compact URL-safe tokens and configurable length, but unlike UUID and ULID it is not a standardized 128-bit layout. Picking the right format depends on whether your priority is interoperability, readability, or short key length.
| Mode | Length | Sortable by time | Embedded timestamp | Typical use |
|---|---|---|---|---|
| UUID v4 | 36 chars | No | No | General random IDs |
| UUID v7 | 36 chars | Yes | Yes | Database keys and ordered events |
| ULID | 26 chars | Yes | Yes | Readable sortable IDs |
| NanoID | 2–64 chars | No | No | Short URL-safe tokens |
Decoding timestamp metadata safely
The decoder helps you inspect identifier provenance without exposing private data. UUID v1 stores a 60-bit timestamp in 100-nanosecond ticks since 1582-10-15, UUID v7 stores Unix milliseconds in its first 48 bits, and ULID stores Unix milliseconds in its first 10 Base32 characters. By decoding locally, you can validate whether IDs were generated at expected times, detect malformed version bits, and compare event ordering across systems. UUID v4 and NanoID intentionally do not include timestamp metadata, so the tool reports format details only for those modes.
Worked examples
UUID v7 timestamp decode
Inputs: UUID v7: 0193f4df-cf76-7d9a-8765-9f7d4e5c0a21
Result: Version 7, RFC variant, timestamp extracted to UTC ISO date
ULID ordering check
Inputs: ULID: 01ARYZ6S410000000000000000
Result: Timestamp prefix maps to 2016-07-30T23:56:16.385Z
NanoID bulk generation
Inputs: Mode NanoID, length 21, count 50
Result: 50 URL-safe identifiers ready to copy as newline list
Glossary
- UUID v7
- A UUID version defined by RFC 9562 that places a Unix millisecond timestamp before random bits for time-ordered values.
- ULID
- Universally Unique Lexicographically Sortable Identifier using Crockford Base32 with a 48-bit time component and 80 random bits.
- NanoID
- A compact random identifier format that uses a customizable alphabet and length, commonly used for URL-safe IDs.
- UUID variant
- Bit pattern inside a UUID that indicates which layout family the identifier follows, such as RFC 4122/9562.
- Timestamp extraction
- Process of reading embedded time bits from an identifier and converting them to a human-readable date.
Related reading
Frequently Asked Questions
Why use UUID Generator?
- Generate UUID v1, v4, and v7 values plus ULID and NanoID from one interface
- Bulk-generate up to 100 identifiers in one click with copy-ready output
- Decode timestamp metadata from UUID v1/v7 and ULID values for audit workflows
- Verify UUID version and variant bits to catch invalid or malformed IDs quickly
Common use cases
- Generate UUID v7 identifiers for database inserts that benefit from chronological index locality
- Create ULIDs for logs and event streams where lexicographic sorting should match creation order
- Produce NanoIDs for short URL-safe keys in client-side apps or temporary links
- Decode an incoming UUID to confirm whether it carries timestamp metadata before storage analysis
Get weekly tool tips & updates
New tools, power-user tips, and productivity hacks — delivered free every Friday.
No spam, ever. Unsubscribe with one click.
Related Developer Tools
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes instantly in your browser. Free, private, and secure for quick checks.
JWT Decoder
Decode and inspect JSON Web Tokens (JWT) online. View header, payload, and expiry. 100% client-side — your token never leaves your browser.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds. Shows UTC, local, and ISO 8601 formats.
Password Generator
Generate strong, secure, random passwords instantly. Uses the Web Crypto API — nothing is sent to any server, so your passwords stay private.
Base64 Encoder & Decoder
Encode text or files to Base64, or decode Base64 strings back to text in seconds. Free, private, and fully in-browser now.
JSON Formatter & Validator
Format, validate, and minify JSON instantly. Includes syntax highlighting, error detection, and a collapsible tree view — free, private, in-browser.
Explore all Developer Tools.