# gskinner/regexr

RegExr is a HTML/JS based tool for creating, testing, and learning about Regular Expressions.

Repository: https://github.com/gskinner/regexr
Canonical: https://ross.abutalabs.com/products/regexr
Homepage: http://regexr.com/
Language: JavaScript
License: GPL-3.0
License Family: copyleft
Last push: 2025-07-17T15:40:23+00:00

## Health v2 (maintenance only)
Score: 37/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 32, release rhythm 8, longevity 100
- inputs: {"age_days": 4562, "days_push": 412, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 10353, forks 1003 (observed 2026-08-28T04:10:41.772653+00:00)

## What it is
RegExr is an HTML/JS web application for creating, testing, and learning about Regular Expressions, with real-time match highlighting, expression explanations, a full reference, and community pattern sharing. It supports JavaScript and PHP/PCRE regex flavors and is the codebase behind regexr.com.

## Use cases
- test regular expressions online
- learn regex syntax with examples
- debug a regex pattern and see matches in real time
- explain what a regular expression means in plain English
- validate regex patterns with test suites
- find and share community regex patterns

## When to choose
- you want an interactive, browser-based regex editor with live match feedback
- you need to learn or teach regular expressions with a built-in reference and cheatsheet
- you work with both JavaScript and PCRE regex flavors
- you want to save and share regex patterns with others

## When to avoid
- you need a command-line or offline-only regex tool
- you need regex flavors beyond JavaScript and PCRE (e.g., .NET, Java, Rust)
- you want programmatic regex testing integrated into a CI pipeline

## Facets
- artifact type: application
- maturity: active
- function: developer-tools, parser, testing, documentation
- domain: developer-tools, web-development, education, tutorials
- platform: browser, cross-platform
- tags: regex, regular-expressions, online-tool, pattern-testing, learning-tool, pcre, javascript, web-server, nodejs

## Member repositories
- gskinner/regexr (main) score 37

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:41.772653+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:19:07.535402+00:00, confidence not recorded.
  - readme: https://github.com/gskinner/regexr (fetched 2026-08-28T04:10:41.772653+00:00, sha 725d45d75c24)
  - homepage: http://regexr.com/ (fetched 2026-08-29T08:18:42.470935+00:00, sha d0d36017038c)
- Data as of 2026-08-30T08:39:29.467469+00:00.