OmniTools

Regex Pattern Tester & Debugger

Test regular expressions in real-time with match highlighting and preset patterns.

Basis: RegExp syntax and flags as defined in the ECMA-262 standard·2026-08-28 verified·Editorial policy

Before you rely on this

This is the JavaScript (ECMA-262) flavour. Patterns do not transfer verbatim to PCRE, Python or Java — recursion and atomic groups are unsupported, and \d and \w match ASCII only unless the unicode flag is set. Patterns with nested quantifiers can slow down sharply on certain inputs.

Tool Overview & Key Purpose

Test regular expression patterns in real time with syntax highlighting, flags (g, i, m), and capture group inspection.

Step-by-Step Usage Instructions

1STEP 1

Enter regular expression pattern into the search bar.

2STEP 2

Toggle regex flags (`g` Global, `i` Case-insensitive, `m` Multiline).

3STEP 3

Paste sample text into the test canvas to view real-time highlighted matches.

4STEP 4

Inspect captured groups ($1, $2) and character match indices.

Real-World Scenarios & Practical Cases

3 Practical CasesScenario #1

Email Address Validation Pattern

Pattern `[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}` extracts valid email addresses from text.

Standard pattern for form validation.Scenario #2

Phone Number Format Extraction

Pattern `\d{3}-\d{3}-\d{4}` locates US style telephone numbers across documents.

Ideal for data sanitization and masking.Scenario #3

HTML Tag Stripping & Data Cleaning

Pattern `<[^>]*>` strips all HTML elements leaving plain unformatted text content.

Crucial for web scraping and text parsing.Regex flavourECMAScript 2024 compliant RegEx matching engine.

Pro Tips & Key Considerations

Enable `g` flag to find all occurrences, not just the first match.Use lazy quantifiers (`.*?`) instead of greedy quantifiers (`.*`) to prevent over-matching.

Frequently Asked Questions (FAQ)

Sources & References

MDN Web Docs — Regular Expressions Guide ECMA-262 — ECMAScript Language Specification (TC39)

Basis: RegExp syntax and flags as defined in the ECMA-262 standard · 2026-08-28 verified