Document Regex Tester

Extract emails, dates, or custom regex matches from text.

JavaScript is required for this interactive tool.Static Reference / Engine Logic:const lines = input.value.split('\n'); if(lines.length < 2) { output.textContent = "Please put your regex on the first line, and the text to search on the subsequent lines.\nExample:\n/[A-Z]+/g\nHere is some TEXT."; return; } const regexStr = lines[0]; const text = lines.slice(1).join('\n'); try { const matchRegex = regexStr.match(/^\/(.*)\/([a-z]*)$/); let regex; if (matchRegex) { regex = new RegExp(matchRegex[1], matchRegex[2]); } else { regex = new RegExp(regexStr, 'g'); } const matches = text.match(regex); if(matches) { output.textContent = `Found ${matches.length} matches:\n\n` + matches.join('\n'); } else { output.textContent = "No matches found."; } } catch(e) { output.textContent = "Invalid regular expression: " + e.message; }

How it works

This tool runs entirely in your browser using vanilla JavaScript. Data is not sent to any server. Mechanically, it processes the input string or array buffer using native web APIs (like WebCrypto, TextEncoder, or regex matching).

Common Use Cases

Debugging broken files.
Verifying data integrity.
Extracting raw data structures.

Document Regex Tester

How it works

Common Use Cases

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