regex replace tool

Advanced Find & Replace with Regex Patterns

Find and replace is essential for refactoring and text transformation, but simple string replacement is limited. You can't easily replace all variations of a pattern, rearrange matched content, or conditionally replace based on context. Manual find-and-replace in an editor is slow for complex changes. This Regex Replace Tool lets you define patterns and see replacements instantly before applying them.

Write a regex pattern, specify a replacement using capture groups, and watch the transformation happen in real time. Perfect for bulk code refactoring, data transformation, and complex text processing.

Powerful Replacement Syntax

Literal Replacement: Simply replace all matches with fixed text.

Capture Group References: Use $1, $2, etc. to reference captured groups, rearranging matched content:

• Pattern: (\\w+)\\s+(\\w+) (first and last name)
• Replacement: $2, $1 (last name, first name)
• Example: "John Smith" → "Smith, John"

Special Replacements:

• $&: The entire matched string
• $`` : Text before the match
• $': Text after the match

Common Code Refactoring Scenarios

Rename Variables Across Files: Find all instances of a variable pattern and rename them. For example, change user_id to userId everywhere:

• Pattern: user_id
• Replacement: userId

For complex patterns like function_name( that vary:

• Pattern: (\\w+_\\w+)\\(
• Replacement: Use a pattern to extract and transform the name

Reformat Data: Transform data formats without manual editing. Convert date formats, phone numbers, or address formats by extracting parts and recombining them:

• Pattern: (\\d{4})-(\\d{2})-(\\d{2}) (YYYY-MM-DD)
• Replacement: $3/$2/$1 (DD/MM/YYYY)

Code Modernization: Update code syntax across files. For example, update import statements, function signatures, or API calls:

• Old: require('module')
• New: import 'module'

HTML/XML Transformation: Restructure or update markup by finding patterns and rewriting them with rearranged content.

Log Cleanup: Remove or transform sensitive data in logs. Find email addresses, phone numbers, or IDs and replace them with redacted versions:

• Pattern: \\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Z|a-z]{2,}\\b
• Replacement: [REDACTED]

Live Preview Before Applying

See the transformation in real time. This is crucial—test your pattern and replacement on a sample before applying to entire documents. Mistakes in find-and-replace can corrupt large files quickly.

Full Regex Flag Support

• g (global): Replace all matches, not just the first
• i (case-insensitive): Replace regardless of case
• m (multiline): Treat line boundaries as match anchors
• s (dotAll): Dot matches newlines

Copy & Use Results

Once satisfied with the transformation, copy the result to your clipboard and paste it directly into your editor or files.

100% Local Processing

All find-and-replace happens in your browser. Your content never leaves your machine, making this safe for proprietary code, sensitive data, or internal documentation.