Regex Tester & Validator

Test and validate regular expressions online against sample text, with quick feedback on matches and groups.

regexvalidatetext

Regex Pattern

Enter the JavaScript regex pattern you want to test.

0 CharactersPattern compiled

Sample Text

Paste the text you want to validate against the regex.

0 Characters0 Lines

Match Results

Preview highlighted matches and inspect their positions and capture groups.

Enter a regex pattern to preview matches.

0 Matches0 Sample characters0 Sample lines

Formatting Options

Preview the shared config renderer across simple, choice-based, and multi-select settings.

Regex flags

Enable the JavaScript regular expression flags you want to test with.

Global (g)

Find all matches instead of stopping at the first.

Ignore case (i)

Match letters without case sensitivity.

Multiline (m)

Treat ^ and $ as line boundaries.

DotAll (s)

Allow . to match newline characters.

Unicode (u)

Enable Unicode-aware parsing.

Sticky (y)

Force matches to start at the current index.

Match mode

Choose whether to inspect the first match or every match in the sample text.

Return every match the pattern finds.

Show capture groups

Display the individual capture groups for each regex match.

Enabled

Overview

Regex is powerful and easy to get wrong. Test regex online against sample text—see matches, capture groups, and errors before you commit. Regex tester, regular expression validator, regex match tool. Refine patterns for form validation, search, or parsing. Online regex checker to validate regex pattern. Catch syntax errors and edge cases. Testing runs locally.

Features

Regex Validation
Test patterns and catch mistakes before using them elsewhere
Match Feedback
See how your regex behaves against real sample input
Pattern Debugging
Refine expressions before adding them to code or forms
Privacy First
All processing happens in your browser

Quick Tips

•Test your regex against both matching and non-matching examples
•Keep patterns readable when teammates may need to maintain them later
•Escape special characters carefully when copying regex into source code
•All data stays in your browser - nothing is sent to servers

When this tool helps

Practical situations where this tool is worth opening.

Validating form-input patterns before adding them to client or server code.
Checking capture groups while parsing logs, identifiers, or URLs.
Comparing how a pattern behaves against matching and non-matching sample text.

Common mistakes to avoid

A few easy ways these workflows go wrong in practice.

Testing only happy-path examples and missing edge cases.
Forgetting that regex syntax can differ between languages and runtimes.
Writing a compact pattern that works today but is too opaque for teammates to maintain later.