How do I reference capture groups in the replacement?

Use $1, $2 and so on for numbered groups, $& for the entire match, and $$ for a literal dollar sign — the same syntax as JavaScript String.replace.

What do the flags do?

Global (g) replaces every match instead of just the first; ignore-case (i) makes matching case-insensitive; multiline (m) makes ^ and $ match line boundaries; dotall (s) lets the dot match newlines.

Is my text uploaded anywhere?

No. The regular expression runs through your browser's built-in JavaScript engine, so your pattern and text stay on your device.

Regex Replace Tool

Find and replace with regular expressions and capture groups.

Find and replace with regular expressions

A focused regex replace tool: enter a pattern, a replacement string, pick your flags, and watch the substituted output update live. Capture-group references ($1, $2, $&) let you reorder and reshape matched text — for example turning 2026-05-28 into 28/05/2026.

Patterns use the standard JavaScript regular-expression engine, so what works here works in your code. Nothing is uploaded; all matching happens in your browser.