Regex playground

Test a pattern against sample text with live highlighting, named capture groups and replacement. It runs in a background worker with a timeout, so a pattern that backtracks catastrophically is abandoned rather than freezing the tab.

Pattern

Test text

ReplacementOptional. $1, $<name> and $& work.

Matches

2026-09-17 09:14:02 INFO  api  request served in 34ms
2026-09-17 09:14:07 WARN  api  upstream retry 1 of 3
2026-09-17 09:14:09 ERROR api  upstream timeout after 5000ms
2026-09-17 09:15:00 INFO  api  request served in 28ms

The pattern runs in a background worker in your browser, with a 1500ms timeout so a runaway expression is abandoned instead of freezing the page. Nothing is uploaded, stored or logged.