Test and validate regular expressions with live preview. Find all matches, check patterns, and share via URL — runs entirely in your browser. This free online regex tester and validator runs entirely in your browser — no data is ever uploaded to a server. How to Use 1. Enter your input — type or paste your regex pattern, flags, and test string. 2. See live results — the tool updates instantly as you type. 3. Copy or download — copy the output to clipboard or download it. 4. History — your recent inputs are saved locally and can be pinned for quick access. Example Pattern ^\d{3}-\d{2}-\d{4}$ (escaped as ^\d{3}-\d{2}-\d{4}$ in the UI) with test string 123-45-6789. It reports "Pattern matches!" and highlights the matched value.