ToolbitRegex Tester and Debugger
Write a pattern and watch it match as you type. Toolbit highlights every match, breaks out capture groups, and previews the result of a replacement before you commit it to code.
What the Regex Tester does
- Live match highlighting over your sample text.
- Named and numbered capture groups listed per match.
- Replace preview with $1 and named group references.
- All JavaScript flags: global, ignore case, multiline, dot-all, unicode, sticky.
How to use it
- Enter your regular expression and pick the flags.
- Paste sample text into the test panel.
- Inspect the highlighted matches and capture groups, then copy the pattern.
Why it runs locally
Toolbit has no backend. The Regex Tester is implemented with standard browser APIs, so your input is processed in the tab and never uploaded, logged, or retained. That is what makes it safe to paste real data into — and it is also why the tool keeps working with the network disconnected, once you have installed Toolbit as an app.
Frequently asked questions
- Which regex flavour does it use?
- JavaScript (ECMAScript) regular expressions, which cover most of what PCRE users expect apart from lookbehind quirks and recursion.
- Can I preview a replacement?
- Yes. The replace field supports $1, $<name>, and $& references and shows the result live.
- Is my sample text uploaded?
- Local transformations process input in your browser. HTTP and WebSocket tools send user-initiated requests. Optional product analytics is off by default, excludes tool input and output, and stays off when your browser signals Do Not Track or Global Privacy Control.