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Regex Helper

For developers who bounce off regex every time they need one. Paste an English description of what you want to match, or an existing regex that's misbehaving, or one you can't read — get back a working pattern targeted at your flavor (JavaScript / Python / PCRE / grep-BRE), a plain-English breakdown of every piece, three example strings it matches, three near-miss strings it does NOT (with the specific reason), and — on the deep tier — the edge cases most people forget plus a catastrophic-backtracking / ReDoS audit and per-flavor portability notes.