Log Pattern Builder
Paste one example log line, and get a matching regex back — with IPs, dates, times, numbers and quoted strings automatically turned into named capture groups.
About this tool
Recognises Apache/Nginx-style bracketed timestamps, IP addresses, ISO dates (2026-03-14), times (10:15:32), double-quoted strings and standalone numbers, tried in that order at each position. Each one becomes a named capture group (timestamp, ip, date, time, field, num, with a number added when a name repeats); everything else is kept as literal text, with regex special characters escaped. The generated pattern is anchored with ^ and $ when it is tested against the lines in the second box, and each line is marked ✓ or ✗ with a count of how many matched. Literal words stay literal, so a line with a different HTTP method or path inside quotes still matches, but one with a different word outside the quotes won't. Always check the result against a few real lines before relying on it.