Regex & Code

Regex & Code — 7 free browser-based developer tools including Regex Tester, Regex Cheatsheet and Cron Expression Generator. Everything runs locally with no signup or uploads, so your data stays private and results are instant.

7 tools

Regex TesterRegex tester that runs regular expressions against your text with real-time highlighted matches, named and numbered capture groups and flag toggles. Preview replacements while you build and debug patterns, free in your browser.

Regex CheatsheetRegex cheatsheet organizing regular expression syntax by category: metacharacters, quantifiers, anchors and groups, all searchable. Copy any pattern in one click, with JavaScript regex compatibility noted, free in your browser.

Cron Expression GeneratorCron expression generator with a visual editor for the minute, hour, day, month and weekday fields, building valid crontab syntax. Preview the next scheduled execution times before you deploy, for free.

SQL FormatterFree online SQL formatter that beautifies and indents queries. Choose 2- or 4-space indentation, uppercase keywords like SELECT and FROM, and pretty-print MySQL and PostgreSQL.

HTML Formatter/MinifierHTML formatter and minifier that beautifies messy markup with clean indentation and line breaks, or strips whitespace to shrink file size. Free and instant in your browser, nothing to install.

CSS Formatter/MinifierCSS formatter and minifier: beautify stylesheets with consistent indentation and line breaks, or strip whitespace and comments to shrink them. Free and instant in your browser, ready for production.

JavaScript Formatter/MinifierJavaScript formatter powered by the Prettier engine for consistent indentation and style, plus a minifier that strips whitespace and comments. Free and instant in your browser, no upload, no install.

How to Use

1
Test the pattern on real input— Paste a sample into the Regex Tester: matches and capture groups are highlighted as you type, so you can see which alternative actually fires before shipping the pattern.
2
Format or minify the code— The CSS, HTML, JavaScript and SQL formatters re-indent a minified file so it can be read, or strip whitespace and comments when you need the smallest payload.
3
Write the schedule with a form— The cron generator builds the expression from the minute, hour, day, month and weekday fields and states in words when the job will actually run.

Frequently Asked Questions

It runs the browser's own JavaScript RegExp engine, so a pattern that matches here matches identically in Node.js and in the browser. Most PCRE patterns carry over, but possessive quantifiers and recursion do not exist in JavaScript, and lookbehind needs a reasonably current browser.

No. The CSS, HTML, JavaScript and SQL formatters only rewrite whitespace, indentation and line breaks. Minify mode also strips comments, so keep a copy of the original if those comments are licence headers you have to preserve.

The five fields are minute, hour, day of month, month and day of week, so that example runs at 03:00 every Monday. The Cron Expression Generator builds the string from dropdowns and previews the next scheduled runs, letting you confirm the schedule before you deploy it.