Regex Tester & Debugger Studio
100% Local Browser ProcessingDeveloper SuiteHow to Test & Debug Regular Expressions
Test JavaScript, PCRE, and Python-compatible regular expressions instantly inside your browser with zero latency and complete privacy.
Enter Regex Pattern & Flags
Type your regular expression pattern in the pattern bar and toggle flags like 'g' (global), 'i' (case-insensitive), or 'm' (multiline).
Paste Test Text String
Paste your source code, log entries, or test text in the left pane to watch matches highlight instantly in real-time.
Inspect Groups or Replace
Extract indexed ($1, $2) and named capture groups, or switch to the Match & Replace tab to test pattern substitutions.
Regular Expression Matching & Extraction Reference
Understand how regex character classes, quantifiers, lookarounds, and backreferences match against raw test input.
| Format Type | Unformatted Input Sample | Matched / Replaced Output | Primary Use Case |
|---|---|---|---|
| Email Validation Pattern | contact alex@meema.in for support | alex@meema.in | Extracting or validating email addresses from text strings |
| Digits & Phone Extraction | Order #9872, Call +1 (555) 234-5678 | 9872, +1 (555) 234-5678 | Parsing numeric order IDs or phone numbers from raw text |
| Named Capture Groups | user_alex | Group 'name': alex | Structuring matched tokens into named JSON key-value pairs |
| Pattern Substitution / Replace | user: secret_pass_123 | user: [REDACTED] | Sanitizing sensitive tokens, credentials, or PII from log files |
Why Use Meema Tools Regex Tester?
Built for maximum web developer productivity, real-time pattern matching, capture group extraction, and 100% client-side security.
Real-Time Pattern Highlighting
Instantly highlight all matching substrings, word boundaries, and character classes with zero latency.
Capture Group Extraction
View indexed capture groups ($1, $2) and named capture groups with detailed offset bounds.
1-Click Match & Replace
Test pattern substitutions using backreferences ($1, $2, $&) in real-time.
Comprehensive Preset Library
Load sample regex patterns for emails, URLs, dates, passwords, and IP addresses with one click.
Frequently Asked Questions
About Regex Testing
Everything you need to know about regular expression testing, flags (g, i, m, s, u, y), capture groups, match replacement, and browser privacy.
100% Confidentiality
All regex matching & text replacement runs locally on your computer. Zero text bytes touch any external server.
Type or paste your regex pattern into the pattern input bar, select your regex flags (g, i, m, s, u, y), and paste your test text in the left pane. Matches are instantly highlighted in real-time with detailed capture group details.
We support all standard ECMAScript regex flags: 'g' (Global search), 'i' (Case-insensitive), 'm' (Multiline mode), 's' (Dotall - dot matches newlines), 'u' (Unicode mode), and 'y' (Sticky mode).
Switch to the 'Match & Replace' tab, enter your replacement string (using $1, $2 for capture group references), and view the instant replaced text output in real-time.
No! All regex compilation, pattern matching, capture group extraction, and text replacement execute 100% locally inside your browser's JavaScript engine. Zero data is sent to external servers.
Yes! We provide built-in presets for popular validation patterns including Email Addresses, URLs, IPv4/IPv6, US/Intl Phone Numbers, Strong Passwords, Hex Colors, and JWT Tokens.
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