Is my text private?
Completely. The editor, the regex engine, and storage all run inside your browser. Your patterns and test text are never sent to a server — there are no uploads and no tracking.
Which regex flavors are supported?
Patterns execute on your browser's native ECMAScript (JavaScript) engine, which fully supports named groups, look-behind, Unicode property escapes and more. For PCRE, Python, .NET, Java, Ruby and Go, common flavor-specific syntax — such as (?P<name>…) groups, \A / \z anchors and POSIX classes — is translated automatically, and anything that can't be represented natively is clearly flagged.
How does the hover linking work?
Every match in your test text is connected to a card in the results panel. Move your cursor over a highlighted match and its card is emphasized; hover a card and the tool scrolls to and highlights that match in the text. It makes complex patterns with many matches easy to follow.
Can I see capture groups?
Yes. Each match lists its numbered and named capture groups with their exact start and end positions, and groups are underlined inside the text. Groups that didn't participate in a match are shown explicitly.
Can I test replacements?
Yes. Switch to Replace mode and enter a replacement string using $1, $2, $<name>, $& and related references. The rewritten output renders live with the replaced spans highlighted.
Are my patterns saved?
Your current workspace is remembered between visits in local storage, and you can save named patterns to a local library backed by IndexedDB. Everything stays on your device; use a shareable link to move a pattern elsewhere.
Does it work offline?
Yes. Once the page has loaded, everything works without a connection, including matching, replacing, and your saved patterns.
