Regex Live Replace

Summary

Type a regex pattern and replacement string to see live substitution results with full backreference support.

How it works

1. Paste or type your input text in the left panel.
2. Enter a regular expression pattern in the Pattern field.
3. Enter a replacement string — use $1, $2 (or \1, \2) for captured groups.
4. Toggle flags: g (global), i (case-insensitive), m (multiline).
5. The right panel updates instantly showing the replaced output.
6. Click "Copy Result" to copy the transformed text to your clipboard.

Use cases

• Rename variables across a code snippet using capture groups.
• Strip or reformat dates, phone numbers, or structured text.
• Test and iterate on regex substitutions before using them in code.
• Convert camelCase identifiers to snake_case with a single pattern.
• Remove HTML tags or unwanted whitespace from copied content.
• Reorder CSV columns by capturing fields and reordering backreferences.
• Batch-rename file name patterns in a manifest or list.
• Preview regex behavior across multiline input before running in production.

Frequently Asked Questions