Validation pattern checks
Test regex rules for emails, numbers, IDs, usernames, or codes before using them in forms and apps.
Test regular expressions quickly so you can debug patterns, validate text rules, inspect matches, and refine regex behavior without leaving the browser.
Enter a regex pattern, add optional flags, then test it against sample text with highlighted matches and match details.
Test regex rules for emails, numbers, IDs, usernames, or codes before using them in forms and apps.
Confirm whether a pattern finds the exact tokens, words, or fragments you expect inside larger text blocks.
Compare how global, case-insensitive, or multiline flags change the result before putting the regex into production code.
Use a pattern like \d+ with the g flag to capture every numeric value in a string.
Add the i flag when the same word may appear in uppercase, lowercase, or mixed case forms.
Use the m flag when testing anchors such as ^ and $ across multi-line input.
Try a pattern directly here to catch invalid escapes, broken character classes, or unsupported flag combinations before they hit your app.
The tester builds a JavaScript regular expression from your pattern and optional flags, then runs it against the provided test text. Matching parts are highlighted in the original text so you can see the behavior clearly.
It also counts total matches and lists matched values separately, which makes it easier to debug whether the regex is too broad, too narrow, or missing expected parts of the text.
If the pattern or flags are invalid, the tool reports an error instead of running the match. That helps you catch syntax problems such as unsupported flags, broken escapes, or malformed expressions early.
Use the JSON Formatter if the same debugging workflow also includes structured payload cleanup.
Open Base64 Encoder Decoder when extracted or validated text also needs encoding work.
Visit the Developer Tools Hub for more browser-based formatting, conversion, and debugging tools.
Regex is powerful, but it is also easy to overmatch, undermatch, or miss important edge cases when you only test patterns mentally or inside scattered code. This tool gives you quick visual feedback so you can refine the pattern faster.
It is especially useful for validation rules, logs, IDs, codes, parsing tasks, and string extraction work where seeing the matched output matters more than reading the pattern alone.
Use it when building input validation, cleaning log parsers, testing search rules, extracting IDs, or debugging how flags affect the same regex pattern.
The match count, highlighted output, and matched values list help you see whether the regex found the right number of matches and whether those matches are actually the values you intended to capture.
Copy the matched values, adjust the pattern and flags, or continue into related tools if the same debugging workflow also involves JSON cleanup, encoding, or text transformation.