This online regex tester supports JavaScript regex patterns and real-time matching.
It also works as a regex validator to check if your patterns match correctly.
One of the fastest free regex tester tools for developers — runs entirely in your browser.
$& = full match, $1 $2 = capture groups. Runs entirely in your browser.
Enter a pattern to see token explanations.
No saved regexes. Saves stay in your browser (localStorage).
See matches update instantly as you type.
Runs 100% locally — no data leaves your browser.
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A regular expression (regex) is a pattern used to match, search, and manipulate text. It is commonly used for validation, parsing, and extracting data from strings in programming and data processing.
You can use flags like global (g), case-insensitive (i), and multiline (m) to modify matching behavior.
Below is an example of a regex pattern and its matches:
\b\d{3}-\d{3}-\d{4}\bCall me at 123-456-7890123-456-7890Regex patterns allow you to match complex text structures using simple rules.
This regex matches US phone numbers in the format XXX-XXX-XXXX.
Try your own regex pattern above to see matches instantly.
Validate structured data using our JSON Validator or format output with our JSON Formatter.
Validate and format structured data alongside your regex workflow.
Validate structured JSON data and catch syntax errors.
Format JSON into a clean, readable structure.
Side-by-side or inline diff for drafts; copy or download a comparison report
Escape and unescape strings for JavaScript, HTML, JSON, Regex, and URL
Unified patch-style diff: line/word/char modes and hide unchanged lines
Parse URLs and extract all components including query parameters
Enter your pattern and paste your test string. This regex tester online tool highlights matches in real time and updates results instantly as you type.
Regex is used to search, match, validate, parse, and extract data from text in code, logs, and inputs—commonly for validation and data processing.
Flags modify matching behavior. Common flags include global (g), case-insensitive (i), and multiline (m). This tool supports JavaScript flags and applies them instantly.
Yes. Use an email regex pattern (or load one from Common Patterns) and test it against sample addresses to verify matching behavior.
Yes. This free regex tester runs in your browser with no signup and no uploads.