Regex Tester & Match Capturing Inspector
Test and debug complex regular expressions with real-time match highlighting, character position indexing, and substitutions.
Options:
Test Subject String
2 lines · 158 charsMatched Tokens & Capture Groups
Instant execution — your data never leaves your browser.Ctrl + Enter to run
Key Engine Capabilities
Engineered for maximum fidelity, RFC standards compliance, and deterministic execution safety.
Real-time regular expression evaluation against input test strings
Inspects full match positions, character indexes, and capture groups
Provides match substitution and string replacement preview
Supports all JavaScript regex flags (g, i, m, s, u)
How to Use Regex Tester & Match Capturing Inspector
Follow these simple steps for deterministic output execution.
01
Define Regex Pattern
Enter your regular expression and flags.
02
Supply Sample Text
Input test strings representing expected user input.
03
Inspect Matched Results
Review matches, positions, and capture group extractions.
Frequently Asked Questions
Technical context and common integration questions.
What does the "g" flag do?
The global flag (g) finds all matches rather than stopping after the first match.
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