Named Group Tester

Parse and display named capture groups from regex patterns

Named Group Tester

Test and extract named capture groups from regular expressions. This tool helps you work with ES2018 named capture groups syntax (?<name>...) in your regex patterns.

Features:

Parse and display all named capture groups from your regex pattern
Test against input text and extract all matches with their named groups
View results in an organized table format
Support for batch processing (one test string per line)
Export results to JSON/CSV format
Comprehensive statistics about matches and groups

Named Group Syntax:

Use (?<name>...) to define a named capture group
Group names must be valid JavaScript identifiers
Example: (?<year>\\d{4})-(?<month>\\d{2})-(?<day>\\d{2})

Instructions:

Enter your regex pattern with named groups
Optionally set regex flags (default: "g" for global matching)
Enter text to test against
Toggle batch mode to test multiple strings (one per line)
Adjust max results limit if needed
Click to see all matches with their named group values

Use Cases:

Parsing and validating structured data (dates, URLs, coordinates)
Extracting specific fields from log files
Testing complex regex patterns before production use
Learning and debugging named capture groups

Key Facts

Category: Development
Input Types: textarea, text, checkbox, number
Output Type: json
Sample Coverage: 4
API Ready: Yes

Overview

The Named Group Tester is a web-based utility for parsing and extracting named capture groups from regular expressions. It supports ES2018 syntax, allowing you to test patterns against input text and view matches with named groups for efficient data extraction and validation.

When to Use

•When extracting specific fields from structured text like dates, URLs, or coordinates.
•When parsing log files or text data to capture named segments for analysis.
•When developing or debugging regex patterns that use named capture groups.

How It Works

•Enter your regex pattern with named groups using the (?<name>...) syntax.
•Input the text to test, with an option for batch mode to process multiple lines.
•Configure regex flags and set a maximum results limit as needed.
•View extracted matches and named groups in a table or export to JSON/CSV.

Use Cases

Extracting and validating dates from text using patterns like (?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2}).

Parsing server logs to capture timestamps, log levels, and messages with named groups.

Testing complex regex patterns with named groups before deploying them in production code.

Examples

1. Extracting Dates from Text

Data Analyst

Background: You have a dataset with date strings in YYYY-MM-DD format that need to be parsed into components.
Problem: Manually splitting date strings is inefficient and prone to errors.
How to Use: Enter the regex pattern (?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2}) and paste the date strings into the text input.
Example Config: Pattern: (?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2}), Flags: g
Outcome: Each date is parsed into named groups year, month, and day, displayed in a table for easy review or export.

2. Batch Processing Log Entries

System Administrator

Background: Server logs contain unstructured entries with timestamps, severity levels, and messages.
Problem: Extracting structured data from log lines manually is time-consuming and error-prone.
How to Use: Enable batch mode, paste multiple log lines, and use a regex pattern to capture named groups for timestamp, level, and message.
Example Config: Pattern: (?<timestamp>\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}) (?<level>\w+) (?<message>.*), Batch Mode: true
Outcome: All log entries are parsed into structured data with named fields, ready for analysis or export to CSV.

Try with Samples

text, regex

Regex Named Capture Groups

Collection of regex patterns using named capture groups for extracting structured data from text. Named groups make patterns more readable and maintainable by assigning meaningful names to captured portions.

title token named

regex

Regex Pattern Alternatives

Multiple ways to write the same regex pattern with different trade-offs in readability, performance, and accuracy

preferred input family regex

regex

Regex Replace Samples

Collection of common and useful regex replacement patterns for text transformation and data cleaning

preferred input family regex

regex

Common Regex Patterns

Commonly used regular expression patterns for validation and matching

preferred input family regex

regex

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FAQ

What is a named capture group in regex?

A named capture group is a part of a regex pattern that captures matched text and assigns it a name, using the syntax (?<name>...).

How do I test a regex pattern with this tool?

Enter your pattern with named groups, input the text, and click to see all matches with their named group values displayed.

Can I process multiple test strings at once?

Yes, enable batch mode to test each line of input as a separate string for batch processing.

What output formats are available?

Results can be viewed in an organized table or exported to JSON or CSV format for further use.

Is there a limit on the number of matches?

You can set a maximum results limit, defaulting to 100, to control the output size and performance.

API Documentation

Request Endpoint

POST /en/api/tools/named-group-tester

Request Parameters

Parameter Name	Type	Required	Description
textInput	textarea	Yes	-
pattern	text	Yes	-
flags	text	No	-
batchMode	checkbox	No	Enable to process each line as a separate test
includeUnmatched	checkbox	No	Show groups with empty/null values in results
maxResults	number	No	-

Response Format

{
  "key": {...},
  "metadata": {
    "key": "value"
  },
  "error": "Error message (optional)",
  "message": "Notification message (optional)"
}

JSON Data: JSON Data

AI MCP Documentation

Add this tool to your MCP server configuration:

{
  "mcpServers": {
    "elysiatools-named-group-tester": {
      "name": "named-group-tester",
      "description": "Parse and display named capture groups from regex patterns",
      "baseUrl": "https://elysiatools.com/mcp/sse?toolId=named-group-tester",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

You can chain multiple tools, e.g.: `https://elysiatools.com/mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp`, max 20 tools.

If you encounter any issues, please contact us at [email protected]

Categories

Named Group Tester