Online Regex Extract & Replace Tool

Regex Extract and Replace Tool

This tool is designed for batch text processing. Extract matching content from large text blocks or replace content according to regex rules. Both functions are available through tabs and support copying and downloading results for later use in scripts, spreadsheets or databases.

Regex Extraction

• Supports common regex flags including global matching (g) and case insensitive matching (i).
• Automatically detects capture groups and allows exporting the complete match or a selected capture group.
• Supports removing empty results and duplicate values, with statistics showing processed counts.
• Click result items to locate and highlight the original matching text.

Output Formats and Export

Extraction results support three formats: one item per line, JSON array and CSV. Line output is convenient for direct copying, JSON is suitable for programs, and CSV escapes commas, quotes and line breaks for spreadsheet compatibility. Results can be copied or downloaded as TXT, JSON or CSV files.

Regex Replacement

Enter a regex pattern, replacement text and source content to perform batch replacement. Replacement supports $1, $2 capture references and $& for the complete match. Empty replacement removes matched content. The preview updates automatically and shows replacement count statistics. Results can be copied or downloaded as TXT files.

Processing Limits

• Text size is classified automatically: under 1MB processes normally, 1MB-8MB may take longer, and larger content should be processed in sections.
• For large text, automatic preview is disabled and replacement execution requires manual confirmation.
• Matching operations have a 100,000 iteration safety limit and prevent infinite loops caused by empty matches.
• Clickable location is enabled only for reasonable result sizes to avoid excessive page rendering.

Error Handling

Invalid regex patterns display compilation errors with engine messages. When no content matches, the tool clearly reports that no result was found instead of returning an empty area. Missing regex or source text is also detected before execution.

Use Cases

• Log analysis: extract IP addresses, timestamps, error codes and API paths.
• Data cleaning: collect emails, phone numbers, order IDs and remove duplicates.
• Content organization: collect URLs and image links into CSV or JSON.
• Batch editing: transform date formats, add prefixes or mask sensitive data.

Privacy and Security

Extraction and replacement use the browser's local regex engine. Regular expressions and processed text are not uploaded or stored, making it suitable for internal data samples and logs.