Regexcellent: Learn Regex

Learn regular expressions by writing them. Regexcellent combines a guided course, a live regex playground, and short challenges in a native app that works offline. LEARN AT YOUR OWN PACE Work through 40 interactive lessons in 8 modules, from literal matches and character classes to groups, backreferences, lookarounds, and practical recipes. Type patterns against sample text, see the matches, and use progressive hints when you need a hand. EXPERIMENT IN THE PLAYGROUND Test patterns with live match highlighting and capture details. Explore token-by-token explanations, toggle matching flags, and save useful patterns on your device. Export supported patterns as Swift, Kotlin, JavaScript, or Python snippets, with warnings when regex engines differ or a translation is unsupported. PRACTICE WITH REGEX GOLF Try 24 challenges and a daily rotating puzzle. Find a working solution, then make it shorter to improve your score. KEEP A REFERENCE CLOSE Search common regex tokens and open working examples in the Playground. BUILD A PRACTICE HABIT Track completed lessons, module badges, and your practice streak. Enable an optional local reminder when it suits you. MAKE IT YOURS Choose System, Light or Dark appearance. Swipe through onboarding with navigation controls always within reach, and see your module badges in a clear three-column layout. OPTIONAL GOOGLE DRIVE SYNC Keep learning progress and saved patterns in sync across Android devices using the same Google account. Sync is off until you choose to connect and confirm what will be copied. Regexcellent uses only its private Google Drive app data, not your ordinary documents. Apple and Android do not sync with one another. Unsaved Playground drafts, reminders and appearance stay on each device. FREE TO LEARN Every lesson and feature is free. The course, reference, challenges and regex engine work offline without an account. There are no ads, app subscriptions or paid feature unlocks. You can optionally support the developer with a one-time tip through Ko-fi, opened in your browser with payment handled by Stripe. Tips unlock nothing and require internet. Optional sync requires internet and a Google account. Built with Jetpack Compose for Android phones and tablets, with light and dark themes and a wider Playground layout on large screens. Regexcellent is for students, developers, and anyone who wants to understand the patterns they use. Start with your first match or use the Playground to explore a pattern of your own.