Regex Tester

Regex Tester

Test regular expressions against text and see all matches with highlighting.

Step 1

Paste input

Add your content in the input editor.

Step 2

Run tool

Process instantly with in-browser logic.

Step 3

Copy output

Export clean results to your project.

All-time runs

Live traffic

30-day success

Reliable processing

Average speed

Fast avg

⚡ Runs instantly in your browser. No files are uploaded.

Pattern

Flags

Test text

Matches

—

Ready.

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About Regex Tester

Writing a regular expression is iterative — the pattern rarely matches exactly on the first attempt. Testing against real data without live feedback means switching between editor, terminal, and documentation constantly. This regex tester accepts a pattern and test text, executes the match using JavaScript's ECMAScript RegExp engine, and highlights every match in real time as you type. Capture group values are listed below. Flags g, i, m, and s are supported. It is used by developers building input validation patte...

Runs locally in your browser. The text you enter is not uploaded to CodeStorms.

→ Test an email or URL validation regex against real addresses before adding it to a form. → Debug a log parsing pattern by running it against a sample of actual log output. → Verify a slug or identifier pattern accepts valid inputs and rejects invalid ones. → Write and test an extraction pattern before applying it to a codebase find-and-replace.

❓ Frequently asked questions 3 answers

This tool uses JavaScript's built-in RegExp engine, which follows the ECMA-262 regex standard.

Yes. Positive and negative lookaheads and lookbehinds are supported in modern browsers.

You can copy the pattern directly. The tool shows the pattern in both literal and string-escaped forms.

Pattern

Flags

Test text

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About Regex Tester

Related guides and workflows

📦 Supported formats 1 file types

❓ Frequently asked questions 3 answers