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Text Extractor via Regular Expressions

Extract matching text using regular expressions and capture groups, output to CSV.

100% Secure - your files are processed in your browser and never sent to a server.
Drop your file hereor click to browseSupports CSV, TSV, or TXT files (.csv, .tsv, .txt) (Max 100MB)

Regular expression extraction is a powerful technique for pulling structured data from unstructured text. This tool applies user-defined regex patterns to text input and extracts all matches into a clean CSV. You can use capture groups to extract specific parts of each match, producing multiple columns from a single regex pattern. The tool is useful for extracting structured data from log files, error messages, configuration output, or any text with repeating patterns. You paste your text, enter a regex pattern, and the tool outputs a CSV with one row per match and columns for each capture group. The regex engine uses JavaScript standard syntax, supporting character classes, quantifiers, lookaheads, and backreferences. All processing runs in your browser, making it safe for extracting patterns from sensitive log files, server output, or confidential documents.

How to use the Regex Extractor tool

  1. Load your text: Drag and drop a text file, choose a file from your file explorer, or paste text directly into the paste area.
  2. Write a regex pattern: Enter a regular expression pattern to match (e.g. (\w+):\s*(\d+)). Use capture groups to extract specific parts.
  3. Configure flags: Toggle Ignore Case for case-insensitive matching and Multiline to make ^ and $ work across lines.
  4. Choose output format: Select CSV (capture groups become columns) or Plain List (matching strings only).
  5. Extract matches: Click the "Extract Matches" button to find all matching text, then copy or download the results.

Frequently asked questions

What regex syntax does the tool support?
The tool uses JavaScript regex syntax, supporting character classes (\d, \w), quantifiers (+, *, ?), capture groups (), lookaheads (?=), backreferences, and flags like global (g) and case-insensitive (i).
How are capture groups mapped to CSV columns?
Each capture group becomes a column in the CSV output. Group 0 (the full match) is column 1, group 1 is column 2, and so on.
Can I extract data from server log files?
Yes. Paste the log content and write a regex pattern matching the data you want to extract (IP addresses, timestamps, error codes, etc.). Each match becomes a CSV row.
Does the tool handle multiline matches?
Yes. The regex engine supports multiline matching with the m flag and dot-all matching with the s flag, allowing patterns to span multiple lines.
Is the extracted data suitable for further analysis?
Yes. The CSV output is clean and structured, ready for import into spreadsheet software, databases, or data analysis tools like Python pandas.

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