Regex Pattern Tester & Match Explainer
REGEX PATTERN & TEST TEXT
| Match # | Full Match | Group 1 | Group 2 |
|---|---|---|---|
| No matches found. | |||
Regular Expression (Regex) Syntax & Pattern Matching Guide
Regular Expressions (Regex) provide pattern matching logic for string validation, log parsing, data sanitization, and text refactoring across programming languages.
Common Pattern Cheat Sheet
- Email Address:
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ - IPv4 Address:
^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$ - URL Protocol:
^https?:\/\/[^\s/$.?#].[^\s]*$
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Frequently Asked Questions
Common questions about this tool.
How does the Regex Tester work? ▼
Enter your regex pattern and target text. The tester evaluates the JavaScript `RegExp` engine in real-time, highlighting matching substrings and capture groups.
What flags are supported? ▼
Supports `g` (Global match), `i` (Case-insensitive), `m` (Multiline), and `s` (Dot matches all newline characters).
Is my input text uploaded to external servers? ▼
100% private. All regular expression evaluations execute locally in your web browser.
How do capture groups work in regular expressions? ▼
Parentheses `(...)` define capture groups. Extracted group values are displayed in a structured match inspection table.
What are common regex patterns? ▼
Common patterns include Email Validation (`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`), URL Extraction, and IPv4 Addresses.
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