RegEx Tester – Online Regular Expression Tool for Developers

Writing and testing regular expressions can be tricky — but with our RegEx Tester, it becomes fast, visual, and error-free. Whether you’re a beginner trying to understand how RegEx works or a seasoned developer refining complex patterns, this tool helps you build and debug regular expressions in real time.

The RegEx Tester allows you to enter your regular expression and instantly test it against sample input text. As you type, matches are highlighted, so you can visually see what works and what doesn’t. It supports all standard regular expression syntax, including groups, quantifiers, lookaheads, character sets, anchors, and more — making it a must-have utility for developers, QA engineers, and data analysts.

Unlike coding in a console or editor with trial-and-error, this tool saves time by providing immediate feedback. You can also toggle case sensitivity, global search, multiline mode, and use replace mode to preview substitution outputs. It’s designed for modern browsers and works smoothly on desktops, tablets, and even smartphones.

Whether you’re parsing logs, validating email addresses, formatting strings, or scraping data, this online regular expression tester is your go-to tool for simplifying and speeding up the process. It also provides quick access to syntax help, cheat sheets, and common pattern examples — so you’re never stuck.

With zero setup and lightning-fast performance, this tool is ideal for web developers, backend engineers, frontend designers, or anyone dealing with text manipulation. If you’re working with JavaScript, Python, PHP, or any language that supports RegEx — you’ll love the simplicity and power this tool brings.