How to Use

Enter a regex

Type a regular expression pattern (e.g., [a-z]+) and choose flags like global (g) or case-insensitive (i).

Add test text

Paste or type sample text in the test string area. Matches are highlighted in real time.

Review matches

See match count, highlighted results, and any capture groups extracted from your pattern.

About Regex Tester

Regular expressions are powerful and unforgiving — a pattern that looks right can silently match the wrong things. ILikePdf Regex Tester highlights matches in real time as you type the pattern and the test string, with flag toggles for global, case-insensitive, and multiline behaviour. Test edge cases like empty strings and unicode before shipping. Everything runs locally in your browser, so test data never leaves your machine.

How to test regular expressions Regex Tester

Step 1: Type your regex pattern in the pattern field.

Step 2: Enter a test string in the input area.

Step 3: Matches highlight in real time as you type.

Step 4: Toggle flags like global, case-insensitive, or multiline.

Step 5: Copy the working pattern into your code.

Common use cases for Regex Tester

Debug regex patterns before shipping them.
Extract patterns from log lines and text files.
Build form validation expressions.
Learn and experiment with JavaScript regex syntax.

Pro tips

Test edge cases — empty strings, repeated matches, and unicode.
Use the global flag to see all matches, not just the first.
Testing is instant and runs locally.

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Regex Tester