Regexion

Regexion — Test. Match. Master.

Regexion is a professional, offline-first regular expression toolkit built for developers. Write, test, debug, and understand regex patterns with real-time matching, highlighted results, and a full explanation of every part of your expression — all without an internet connection.

Live Regex Tester
Type a pattern and see it match instantly against your test text. Every match is highlighted inline, with a dedicated panel showing capture groups — including named groups — and a live match count.

Replace Preview
Write a replacement expression and see a clean before/after comparison before you commit to it, with one-tap copy of the result.

Regex Explanation
Every character class, quantifier, group, anchor, lookahead, and lookbehind in your pattern is broken down into plain English, so you can understand exactly what a pattern does — or learn regex as you go.

Saved Patterns
Save unlimited regex patterns, organized into categories like Email, URL, Password, Phone, Date, HTML, JSON, and your own custom category. Regexion ships with a curated starter library so you're never starting from a blank screen.

Cheat Sheet
A built-in, always-available reference covering character classes, quantifiers, assertions, groups, flags, and escaping — with examples for each.

History & Favorites
Every pattern you test is automatically logged so you can pick up where you left off. Bookmark the patterns you use most for one-tap access.

Search
Find any saved pattern instantly by name, pattern text, category, or example.

Offline & Private
Regexion never asks for an internet connection and never collects personal data. Everything — your patterns, your history, your settings — stays on your device. Import and export use Android's Storage Access Framework, so you're always in control of your own files.

Built for Performance
A native Kotlin and Jetpack Compose app with Material Design 3, smooth animations, and a fast Kotlin regex engine, Regexion is designed to feel instant no matter how large your test text is.

Why developers choose Regexion
Whether you're validating a form field, parsing a log file, writing a scraper, or just learning regular expressions for the first time, Regexion gives you a fast, focused, distraction-free workspace — with the reference material built right in.

Download Regexion and never second-guess a regular expression again.