Online regular expression find & replace - Capture groups, multiple modes, real-time preview
Use parentheses () in the regex to create capture groups, then reference them in the replacement with $1, $2, $3, etc. $& represents the entire match, $` is the text before the match, $' is the text after. Example: (\w+)@(\w+)\.com replaced with $1[at]$2.com.
g=global (match all occurrences, not just the first); i=case-insensitive; m=multiline (^ and $ match line start/end); s=dotAll (. also matches newlines). Flags can be combined, e.g., e.g., gi means global + case-insensitive.
Supports JavaScript standard regex: character classes \d\w\s, quantifiers +*?{n,m}, groups (), alternation |, anchors ^$, lookaheads (?=)(?!), lookbehinds (?<=)(?
No. Regex Replace Tool uses client-side processing β everything runs in your browser. Your data never leaves your device, and the tool works even without an internet connection.
Yes, Regex Replace Tool is completely free to use. No registration or login required β all features are available immediately.
Absolutely. All processing happens locally in your browser. No data is sent to any server, so there's zero risk of data leaks. Your information stays completely under your control.
Regex Replace Tool has no usage limits β it's free and unlimited. Since processing is done client-side, speed depends on your device. For very large files, we recommend processing in batches for the best experience.
No. Regex Replace Tool is a web-based tool β just open it in your browser and start using it. No downloads, plugins, or extensions required.