Paste any regular expression and get a plain-English explanation of every part. Decode complex patterns, learn regex syntax, debug expressions, and test against sample text. Free, private, no login required.
Enter a regular expression above and click "Explain Regex" to see a token-by-token breakdown.
Follow these simple steps to understand any regex pattern. It takes just seconds — no prior regex knowledge required.
Enter any regex pattern in the input field — from simple patterns like \d+ to complex ones with lookaheads, character classes, and alternation. Paste from your code editor or type it directly.
Choose the regex flags to apply: g (global), i (case-insensitive), m (multiline), s (dotall), or u (Unicode). Each flag modifies how the engine interprets the pattern.
Press "Explain Regex" to see a color-coded breakdown. Every token is displayed with its regex syntax in monospace and a plain-English description of what it matches or asserts.
Paste sample text to see all matches highlighted in real time. The tool shows total match count and visually marks each match so you can verify the regex does exactly what you intend.
A fast, private, and feature-rich regular expression explainer built by professional developers at CoderDesign Toronto. Here is what makes it different.
Every token in your regex is explained in simple, human-readable language. Anchors, quantifiers, character classes, groups, lookaheads — all decoded instantly so you never have to guess what a pattern does.
The regex is parsed entirely client-side using a deterministic tokenizer written in TypeScript. No server calls, no latency — just paste your regex and see the breakdown in milliseconds.
Nothing you type ever leaves your browser. Your regex patterns and test strings are never sent to any server, stored in any database, or shared with any third party. Complete privacy guaranteed.
Paste any text in the test area to see exactly which substrings your regex matches. Matches are highlighted inline with a count badge so you can verify and debug patterns instantly.
Perfect for students and developers learning regular expressions. See every part of a pattern explained with color-coded token types — anchors, quantifiers, groups, and more — to build intuition by example.
Fully responsive design that works on desktop, tablet, and mobile. Chrome, Firefox, Safari, Edge — all modern browsers supported. No installation or plugins required.
See how developers, students, code reviewers, and teams use the Regex Explainer to work smarter with regular expressions.
Students and beginners can paste any regex pattern and instantly see what each part does. Build understanding of anchors, quantifiers, groups, and character classes by seeing real explanations instead of abstract documentation.
When a regex doesn't match what you expect, paste it here to see the precise meaning of every token. Spot misplaced quantifiers, missing escapes, or incorrect character classes in seconds instead of staring at cryptic syntax.
Inherited a codebase full of regular expressions? Paste each one to get a clear English summary of what it validates or extracts. Perfect for code reviews, onboarding, and legacy system documentation.
Use the explainer as a feedback loop while authoring regex. Write your pattern, see the explanation, verify it matches your intent, and iterate until the English description matches what you want the regex to do.
Copy the plain-English explanation and paste it as a code comment or into team documentation. Transform unreadable regex into clear descriptions that any team member can understand without regex expertise.
Everything you need to know about explaining and understanding regular expressions. Can't find what you're looking for? Contact us.
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