Why this pattern string generator?
- Create business-style IDs from dates, sequences, and random tokens.
- Preview first 20 lines and export in multiple formats.
- Share settings safely—output never appears in URLs.
- Seeded mode enables reproducible test data.
Quick presets
Pick a preset to fill the pattern box, then tweak tokens as needed.
Generate
Pattern string generator
Enter a pattern, choose output settings, then generate lines, CSV, or JSON array.
Token reference
| Token | Example | Description |
|---|---|---|
{A:n} |
{A:3} |
Uppercase letters (A-Z). |
{a:n} |
{a:4} |
Lowercase letters (a-z). |
{9:n} |
{9:6} |
Digits (0-9). |
{alnum:n} |
{alnum:8} |
Alphanumeric (A-Z, a-z, 0-9). |
{hex:n} |
{hex:8,upper=true} |
Hex characters, optional uppercase. |
{chars:n,SET} |
{chars:10,ABCDEFGHJKLMNPQRSTUVWXYZ23456789} |
Random characters from a custom set. |
{uuid} |
{uuid} |
UUID v4 string. |
{date:FORMAT} |
{date:YYYYMMDD} |
Generation time formatted as YYYY MM DD HH mm ss. |
{randdate:start,end} |
{randdate:2025-01-01,2025-12-31,format=YYYY-MM-DD} |
Random date/time between start and end (local time). |
{randint:min,max} |
{randint:0,999999,pad=6} |
Random integer in range, optional zero padding. |
{choice:v1|v2} |
{choice:BUG|REQ|SUP} |
Pick one of the listed values. |
{seq} |
{seq:pad=6,start=1} |
Sequential numbers (start/step/pad). |
Examples
- INV-{date:YYYYMM}-{seq:pad=6,start=1} → INV-202601-000001
- ORD-{date:YYYYMMDD}-{hex:8} → ORD-20260119-3f8a9c1d
- DLV-{randdate:2025-01-01,2025-12-31,format=YYYYMMDD}-{chars:6,ABCDEFGHJKLMNPQRSTUVWXYZ23456789} → DLV-20250714-K8Q2ZP
- USR-{A:3}{9:6} → USR-ABC123456
- X\{Y\}-{A:2} → X{Y}-QZ
FAQ
Is my data uploaded?
No. Everything runs locally in your browser.
Can I share generated IDs with a URL?
Share URLs include settings only. Use copy/download to share output.
Is seeded mode secure?
No. Seeded mode is for reproducibility only.
Can I exclude the pattern from share URLs?
Yes. Turn off include pattern and share settings without exposing the pattern.