How it works, what you get, limits
What it does
Try a pattern in the browser and see hit offsets.
How to use
Enter a pattern and sample, or pick email / phone / URL / date templates.
What you get
Offsets and matched text. Nothing is uploaded.
Options and comparison
Flags g i m s u. Long text is truncated.
Extract lists groups; replace writes a new draft.
Limits
Bad patterns error. Catastrophic backtracking may freeze the tab.
FAQ
Is the text uploaded?
No. The pattern runs in this browser.
Are templates a full spec?
No. They cover common email, phone, URL and date shapes.