Regex Replace
Regex Replace
Preview regex replacement with capture groups before applying to real data.
Processed locally in your browser. We do not store or upload your data.
InputsReplaceInput: manualPreview empty
File input
Choose a file
Click, drop, or paste from clipboard.
Flags
Input: manual
Result
Ready to replace.
Use $1, $2, etc. to reference capture groups in replacement text.
Flow
- Compile regex with selected flags.
- Apply replacement string including capture groups like $1.
- Render transformed output as preview.
Example
Worked example: rename order IDs
- 1 Pattern = order-(\\d+), replacement = invoice-$1
- 2 Input includes multiple order lines.
- 3 Output replaces each order prefix while preserving numeric group.
Capture-group replacement is verified before production usage.
How
- Provide pattern, replacement, and input text.
- Select relevant flags for scope and matching behavior.
- Run replacement and inspect preview output.
Cases
- Batch rename identifier formats in exported data.
- Normalize logs by replacing sensitive value patterns.
- Prototype replacement expressions before writing automation.
Avoid
- Forgetting capture-group references in replacement text.
- Running replacement without Global flag for multi-match input.
- Applying greedy patterns that replace more text than intended.
FAQ
Can I use capture groups like $1?
Yes, replacement strings support capture-group references such as $1 and $2.
Does the tool modify files directly?
No, it only previews output text in your browser.
Can I test multiline replacements?
Yes, enable multiline and other flags as needed.
Switch
Switch12
No match.