Regex Tester, Debugger & Visual Cheat Sheet
Test and debug regular expressions online with real-time match highlighting, flag toggles, capture group tables, and an interactive regex cheat sheet.
| # | Index | Matched Value | Capture Groups ($1, $2...) |
|---|---|---|---|
| 1 | 14 | santanu@alltoolss.com | $1: santanu$2: alltoolss.com |
| 2 | 36 | support@google.com | $1: support$2: google.com |
| 3 | 70 | lead.architect@company.co.in | $1: lead.architect$2: company.co.in |
How to Use Regex Tester & VM
- Enter your regular expression pattern in the pattern input bar.
- Toggle regex flags such as Global (g), Case-Insensitive (i), and Multiline (m).
- Type or paste your test text in the test string area.
- Inspect highlighted match results, capture group indices, and replacement output.
Key Features & Security Standards
Client-Side & In-Memory Privacy
All computations, transformations, and string manipulations execute in your local browser memory or isolated ephemeral worker instances with zero permanent disk persistence.
Zero File or Data Retention
Your sensitive files, JWT keys, credentials, and code snippets are never shared, logged, or indexed. Data is automatically flushed as soon as your browser tab closes.
100% Free & Unlimited Usage
No credit cards, sign-ups, subscriptions, or watermarks. All Regex Tester & VM features are accessible without rate limitations or intrusive paywalls.
Frequently Asked Questions
Which regex flavors are supported?+
The tester supports ECMAScript (JavaScript), Python re, PCRE, Golang, and Java compatible regular expressions.
How do I match an email address with regex?+
A standard robust pattern is ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ which validates username, domain, and TLD.
Does this tool work completely offline in browser?+
Yes, regular expression evaluation is performed in-browser using your local JavaScript engine.