Free Regex Cheat Sheet & Pattern Builder
Visual regex reference with click-to-insert patterns, live preview, common patterns library, and code export. 100% client-side — your data stays private.
How to Use the Regex Cheat Sheet
- Click pattern buttons to insert regex tokens into the pattern builder.
- Type a test string and see matches highlighted in real time.
- Use common patterns as starting points for emails, URLs, dates, etc.
- Choose regex flags (g, i, m) from the dropdown.
- Export your pattern as JavaScript, Python, Go, or Java code.
Why Use This Regex Tool
Regular expressions are powerful but notoriously hard to remember. This visual cheat sheet lets you browse patterns by category and insert them with a click — no memorization required.
The live preview shows you exactly what your regex matches in real time, eliminating the trial-and-error cycle. Export directly to your preferred language and paste into your code.
Frequently Asked Questions
g — global: find all matches, not just the first. i — case-insensitive. m — multiline: ^ and $ match line starts/ends, not just string start/end.
Check for escaped special characters (e.g., \. instead of .), ensure the g flag is set for multiple matches, and verify your test string matches the expected format.
Basic patterns are compatible across most languages. However, advanced features like lookaheads or named groups have syntax differences between JavaScript, Python, Go, and Java. The export feature generates language-specific code.
Use Cases
Syntax Reference
Quick regex syntax reference with click-to-insert patterns for common operations.
Quantifier Lookup
Look up regex quantifiers like *, +, ?, and {n,m} for pattern construction.
Character Classes
Find regex character classes for matching digits, words, whitespace, and custom sets.
Pattern Building
Build regex patterns from a visual reference without memorizing complex syntax.
Anchors & Groups
Learn regex anchors, groups, and lookaheads with interactive examples and export.