RegExr
RegExr is a free web tool for learning, building, and testing regular expressions.
What RegExr is
RegExr is a free web tool for learning, building, and testing regular expressions. It supports JavaScript and PHP/PCRE syntax, with results that refresh as you type. Hover over a match or expression to see details, use Explain for a plain-English description, or open Details to inspect capture groups. Tests mode lets you assemble examples the expression should accept and reject. Replace and List generate custom outputs. For learning, the site includes a cheatsheet, reference, help, and examples, and lets users search and rate Community Patterns. You can save and share expressions; signing in keeps favorites and patterns in My Patterns. Saved expressions get public links, but Community-shared copies cannot be edited or deleted. The README credits Grant Skinner and gskinner.com as creators and identifies this version as GPL v3 licensed. It directs issue and feature requests to GitHub and regular-expression questions to Stack Overflow.
Good
- Free plan; available on the web.
- Live results update while you type.
- Tests mode checks expected matches and non-matches.
- Explain describes expressions in plain English.
- Includes reference materials, help, and examples.
Watch out
- Community-shared copies cannot be edited or deleted.
- Available platform is web only.
Who it suits
RegExr suits people who want to learn or work with JavaScript or PHP/PCRE regular expressions in a browser. Its reference materials, live feedback, and test-building tools are useful for both learning and checking expressions.
Verdict
RegExr combines expression editing, testing, and learning resources in a free web tool. Keep in mind that a Community-shared copy cannot later be changed or removed.
Plans and prices
From RegExr's own pricing page, checked 5 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| RegExr | Free | Online regex learning, building, and testing tool |
The facts
Each one read from RegExr's own pages, with the date it was checked.
What it does
- Account storage
- Signing in lets users persist favorites and patterns, which are shown in My Patterns.checked 5 Oct 2026
- Community
- Users can search for and rate Community Patterns.checked 5 Oct 2026
- Creator
- The project README says RegExr was created by Grant Skinner and gskinner.com.checked 5 Oct 2026
- Explain
- The Explain tool describes an expression in plain English.checked 5 Oct 2026
- Learning resources
- The site includes a cheatsheet, full reference, help, and examples.checked 5 Oct 2026
- License
- The project README says this version of RegExr is licensed under GPL v3.checked 5 Oct 2026
- Live results
- Results update in real time as you type.checked 5 Oct 2026
- Match details
- Rolling over a match or expression displays details.checked 5 Oct 2026
- Purpose
- RegExr is an online tool to learn, build, and test regular expressions.checked 5 Oct 2026
- Regex flavors
- RegExr supports JavaScript and PHP/PCRE regular expressions.checked 5 Oct 2026
- Save and share
- Users can save and share expressions with others and the Community.checked 5 Oct 2026
- Sharing limit
- The site says saving creates a shareable public link and that a shared Community copy cannot be edited or deleted.checked 5 Oct 2026
- Support
- The project README directs users to GitHub for issues and feature requests and Stack Overflow for regular-expression questions.checked 5 Oct 2026
- Tests
- Tests mode lets users build a suite of tests that an expression should or should not match.checked 5 Oct 2026
- Tools
- The Replace and List tools output custom results, and Details lists capture groups.checked 5 Oct 2026
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