Regex Tester
Test regex patterns with live highlighting. Generate code for JS, Python, PHP.
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What are Regular Expressions?
Regular expressions (regex) are patterns that describe sets of strings. They are used in virtually every programming language for searching, matching, and replacing text. A regex like \w+@\w+\.\w+ matches email addresses by specifying the pattern of characters before and after the @ symbol.
Common Regex Flags
The global flag (g) finds all matches instead of stopping at the first one. Case-insensitive (i) ignores uppercase/lowercase differences. Multiline (m) makes ^ and $ match line boundaries instead of string boundaries. Dotall (s) makes the dot character match newlines.
Privacy Advantage
Unlike regex101.com, this tool processes all patterns and test strings entirely in your browser. No data is sent to any server, making it safe to test regex patterns against sensitive data like API keys, personal information, or proprietary content.
Frequently Asked Questions
What are the most common regex patterns?
Email validation: [\w.+-]+@[\w-]+\.[\w.]+. URL matching: https?://[\w.-]+(/[\w.-]*)*. Phone numbers: \+?\d{1,3}[-.\s]?\d{3,4}[-.\s]?\d{4}. IP addresses: \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}. Dates: \d{4}-\d{2}-\d{2}. This tool lets you test any pattern against your own data instantly.
What do regex flags g, i, m, and s mean?
The g (global) flag finds all matches instead of stopping at the first. The i (case-insensitive) flag ignores uppercase/lowercase. The m (multiline) flag makes ^ and $ match line boundaries. The s (dotall) flag makes the dot match newlines. Toggle these flags in the pattern bar above.
How is this different from regex101?
ToolPry runs entirely in your browser — no data is sent to any server. On regex101, your patterns and test strings are processed on their servers and may be stored. If you are testing patterns against sensitive data like API keys, passwords, or personal information, ToolPry is the safer choice.
Can I generate code from my regex pattern?
Yes. After testing your pattern, click JavaScript, Python, or PHP to generate ready-to-use code snippets. The generated code includes the correct syntax for each language with your pattern and flags already applied.
How to Use the Regex Tester
Enter your regular expression in the pattern field and your test string in the text area. Matches are highlighted in real time as you type — no need to click a button. The match details panel shows each match's position, length, and capture group values, which is essential for debugging complex patterns with named or numbered groups.
Most Useful Regex Patterns (Copy-Ready)
Email address: /^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$/ — covers 99%+ of real-world addresses. See our full guide: Email Validation Regex Complete Guide.
URL: /https?:\/\/[^\s<>"{}|\^[\]`]+/g — matches HTTP and HTTPS URLs in text.
IPv4 address: /^(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)$/
ISO date (YYYY-MM-DD): /^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$/
Hex colour: /^#([0-9A-Fa-f]{3}|[0-9A-Fa-f]{6})$/
Understanding Flags
The g (global) flag finds all matches, not just the first. The i (case-insensitive) flag ignores case so /hello/i matches "Hello", "HELLO", and "hello". The m (multiline) flag makes ^ and $ match line boundaries instead of string boundaries. The s (dotAll) flag makes . match newline characters, which it does not by default.
Frequently Asked Questions
Which regex engine does this tester use?
JavaScript's built-in RegExp engine (ECMAScript 2024). This is the correct engine for any pattern you intend to use in a browser, Node.js, or Deno application. For Python, Java, or .NET patterns, note that some syntax differs — particularly around lookaheads, named groups, and certain character class syntax.
How do I match a literal dot or plus sign?
Escape special characters with a backslash: \. matches a literal dot, \+ matches a literal plus. The characters . * + ? ^ $ {} [] | \ ( ) all have special meaning in regex and must be escaped to match literally.
Why does my pattern match more than I expect?
Quantifiers are greedy by default — they match as much as possible. Add ? after a quantifier to make it lazy (match as little as possible): .*? instead of .*. Also ensure you have anchors (^ at start, $ at end) if you want to match the entire string rather than a substring.