Regex Tester

What is a Regex Tester?

A Regex Tester applies a regular expression to your text and shows the result live while you type. Matched pieces are highlighted, a match counter updates on every keystroke, and invalid patterns explain their error instead of failing silently.

Which flags are supported?

• g — global: find all matches instead of just the first.
• i — ignore case: a matches both a and A.
• m — multiline: ^ and $ match line starts and ends.
• s — dot-all: . also matches newline characters.
• u — unicode: enables unicode-aware escapes such as \p{...}.

How do I anchor my pattern?

Use ^ to anchor to the start of the text and $ to the end. Without anchors a pattern matches anywhere in the text. Add \b word boundaries for whole-word matching and use parentheses to capture groups you want to reuse.

Is my data safe?

Yes. Matching runs entirely on your device; your pattern and test text never leave the browser. Log lines, tokens or code samples can be tested here safely.

How to use Regex Tester

Write a pattern, pick flags, and see every match highlighted as you type.

Use the controls above to provide your input or choose options, then review the result on the page.

Why use our Regex Tester

• Tests a regular expression against your text live and highlights every match.
• Complete the task with a focused Regex Tester workflow instead of switching between apps.
• Open it in your browser and get started—no account or installation required.