Developer Tools

Regex Tester

Free Regex Tester with flags, highlighted matches, match count, positions, capturing groups, errors, explanation panel, copy regex, clear, and recent patterns. No sign up required.

Free browser developer tool

Regex Tester

Test regular expressions against sample text, highlight matches, inspect capture groups, and keep recent patterns in your browser.

Common token guide

  • \\d digit
  • \\w word character
  • \\s whitespace
  • + one or more
  • * zero or more
  • ? optional
  • () capturing group
  • [] character set
  • ^ line start
  • $ line end

Recent patterns

    Ready. Test regex patterns with JavaScript regex behavior.

    Buy me a coffee

    Mirown is free to use, if this tool saves your time

    Free developer tool

    Use the free Regex Tester online with no sign up or login required.

    Test regular expressions against sample text, highlight matches, inspect capture groups, and keep recent patterns in your browser. Mirown keeps developer pages practical: fast static pages, clear controls, readable output, and no unnecessary account wall.

    This developer tool is built for quick browser work. You can paste code or text, process it on the page, review warnings or output, copy results, and download files without opening a heavy IDE or creating an account.

    Browser-first workflow

    Use the tool directly in your browser with no sign up, no login, and no upload-based storage requirement for normal processing.

    Useful output

    Readable editors, line numbers, copy buttons, download options, validation messages, warnings, previews, and local recent history make everyday developer tasks faster.

    Focused page

    Each Mirown developer tool has its own URL, title, description, instructions, FAQ, and related links so the correct tool is easy to find and open.

    How to use this tool

    1. Open the free Mirown Regex Tester page in your browser.
    2. Paste code, text, JSON, CSS, HTML, JavaScript, or regex test content into the visible editor.
    3. Use the format, minify, validate, test, preview, copy, or download controls for the task.
    4. Check the output, errors, warnings, stats, or match details before using the result in real work.

    What this free tool includes

    • Regex pattern input
    • Test text textarea
    • Flags for global, ignore case, multiline, dotAll, and unicode
    • Highlight all matches in test text
    • Match count and match positions
    • Capturing group display
    • Clear regex errors
    • Simple explanation panel for common tokens
    • Copy regex button
    • Clear button
    • Recent regex patterns saved in local storage
    • Free to use with no sign up or login required

    Why this developer tool is useful

    The Regex Tester helps with log parsing, form validation, text extraction, developer debugging, search pattern testing. It is useful when you need a quick check, cleanup, preview, minified file, or copied result without opening a heavy IDE workflow.

    Privacy note

    Mirown developer tools are browser-first and do not require sign up or login. Recent input is stored only in your own browser local storage when the tool supports it. Avoid pasting private production secrets, access tokens, or sensitive customer data into any website.

    Accuracy note

    Browser developer tools are convenience helpers. Minifiers, validators, formatters, previews, and regex tests should be reviewed before production use, especially when code is complex, security-sensitive, or business-critical.

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    Frequently asked questions

    Is this developer tool free?

    Yes. Mirown Regex Tester is free to use with no sign up or login required.

    Does this tool run in my browser?

    Yes. The visible processing for this tool runs on the page in your browser. Some tools also save recent input in your browser local storage for convenience.

    Can I copy or download the output?

    Yes. Developer tools include copy controls, and tools that produce file-style output also include download options where useful.

    Should I paste private secrets into this page?

    No. Even with browser-first tools, you should avoid pasting passwords, private API keys, access tokens, customer records, or sensitive production secrets into any website.

    Regex testing example

    Test patterns against real text before using them in code.

    Regex testing is useful when you need to match emails, IDs, words, codes, dates, URLs, or repeated formats. A visible match preview helps you understand whether the pattern is too broad or too strict.

    Example workflow
    Input

    Pattern: \b\w+@\w+\.com\b, text: contact hello@example.com today.

    Result

    See match count, positions, highlighted matches, groups, and regex errors before using the pattern.

    Best use cases

    • Test validation patterns before adding them to a form.
    • Check extraction patterns for emails, codes, dates, URLs, and repeated text.
    • Understand flags such as global, ignore case, multiline, dotAll, and unicode.

    Mistakes to avoid

    • Avoid patterns that match too much text because of greedy operators.
    • Use anchors carefully when checking full-string validation.
    • Test several examples, including wrong examples, before relying on a regex in production.
    Why does my regex match more than expected?

    Greedy operators, missing anchors, or broad character classes can match too much. Test with multiple examples and review highlighted matches.

    Which regex flag should I use for all matches?

    Use the global flag when you want to find every match instead of only the first match.

    What this developer tool can and cannot guarantee

    Can help with

    It can format, validate, preview, encode, decode, generate, or inspect code and text locally for the main workflow.

    Important limit

    It cannot guarantee production correctness, security, compatibility, or schema meaning in your real project. Review and test output before deployment.

    Learn more

    Use these Mirown learn pages to understand settings, limits, examples, and safer browser-first workflows before relying on an important result.

    Helpful Mirown guides

    These guides add context, examples, privacy notes, and practical limits for related Mirown workflows.

    People also use

    Continue the same workflow with useful Mirown tools that are internally linked for easier navigation.

    Developer ToolsJSON FormatterFormat and validate JSON.Developer ToolsCSS MinifierMinify CSS for smaller files.Developer ToolsJS MinifierMinify JavaScript snippets.Developer ToolsHTML FormatterFormat HTML markup.Developer ToolsBase64 Encode DecodeEncode and decode Base64 text.Developer ToolsURL Encode DecodeEncode and decode URL strings.Developer ToolsJWT DecoderDecode JWT payloads locally without verification.Developer ToolsSQL FormatterFormat SQL queries for readability.

    Why Mirown is built this way

    Free tools, clear pages, and browser-first privacy.

    Mirown is built by founder Hanan Asif to make everyday document, image, text, QR, calculator, developer, color, business, security, and fun tools easier to use without unnecessary sign up or server storage for the main browser workflows. Important pages explain what the tool can do, what users should review, and where browser limits may apply.

    No sign up required Open a tool, use it, and continue your work without creating an account.
    Browser-first tools Many tools process files, text, and values directly on your device where browser support allows it.
    Transparent limits Important pages explain how the tool works, what to review, and when browser limits can matter.
    Useful guides Mirown guides connect related tools with examples, safe workflow notes, and practical decisions before download.
    Learn articles Evergreen articles explain common searches like PDF compression, WiFi QR codes, image formats, word count, and JSON validation.