The Regex Coach
The Regex Coach is a free graphical application for exploring Perl-compatible regular expressions interactively.
What The Regex Coach is
The Regex Coach is a free graphical application for exploring Perl-compatible regular expressions interactively. It indicates whether a pattern matches a target string and updates the rest of the interface when either changes. Users can highlight captured groups or selected parts of a regex in the target text. The program can explain a pattern in plain English, show its parse tree graphically, and step through the matching process. It also simulates Perl split and substitution operations. Written in Common Lisp, it uses CL-PPCRE as its regex engine. The current Windows download is version 0.9.2, and the maker says the program has not changed since 2008. Linux is no longer maintained, though an unsupported 0.8.5 release is available and also runs on FreeBSD. There is no Mac version planned. The maker supplies the program as-is without warranty and does not promise support for older Windows configurations or the unsupported Linux release. The regex engine may overflow its stack with relatively long patterns.
Good
- Shows match status as patterns and target text change.
- Highlights captured groups or selected regex parts.
- Explains patterns in plain English and with a parse tree.
- Can step through matching and simulate split or substitution.
- Free for private and non-commercial use.
Watch out
- No Mac version is planned.
- Linux release is unsupported and no longer maintained.
- The program has not changed since 2008.
- Long regular expressions may cause a stack overflow.
Who it suits
It suits programmers working with Perl-compatible regex toolkits such as PCRE or CL-PPCRE who want to inspect matching behavior visually. Its lack of a Mac version and unsupported Linux release make platform choice important.
Verdict
The Regex Coach offers several ways to inspect and understand Perl-compatible patterns, including live matching and step-through debugging. It is most suitable when its older Windows release or unsupported Linux build fits your environment.
Plans and prices
From The Regex Coach's own pricing page, checked 2 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| The Regex Coach | Free | Free for private and non-commercial use · Commercial use is free, but redistribution or charging money requires written permission |
The facts
Each one read from The Regex Coach's own pages, with the date it was checked.
What it does
- Engine and implementation
- The application is written in Common Lisp and uses CL-PPCRE as its regex engine.checked 2 Oct 2026
- Intended users
- The maker says it may be useful to programmers using Perl-compatible regex toolkits such as PCRE or CL-PPCRE.checked 2 Oct 2026
- Known limitations
- The regex engine may encounter a stack overflow on relatively long regular expressions, and the maker notes possible issues on Eastern European Windows versions using character set 1250 or similar.checked 2 Oct 2026
- Live matching
- It shows whether a regex matches a target string and updates other parts of the application in real time when you make changes.checked 2 Oct 2026
- Matching stepper
- It can single-step through the matching process performed by its regex engine.checked 2 Oct 2026
- Match inspection
- It can highlight captured groups or selected parts of a regular expression in the target string.checked 2 Oct 2026
- Privacy and security
- The maker's website privacy notice says its server logs may include IP addresses and other access data, and that anonymous log data is stored separately from personal data supplied by users.checked 2 Oct 2026
- Support and warranty
- The program is provided as-is with no warranty, and the maker says not to expect support for older Windows configurations or the unsupported Linux release.checked 2 Oct 2026
- Text operations
- It simulates Perl's split and substitution operators.checked 2 Oct 2026
- What it does
- The Regex Coach is a graphical application for interactively experimenting with Perl-compatible regular expressions.checked 2 Oct 2026
Where it runs
- Linux availability
- Linux is no longer maintained, but the maker provides the unsupported 0.8.5 release, which also runs on FreeBSD.checked 2 Oct 2026
- Mac availability
- The maker says there is no Mac version and no plan to release one.checked 2 Oct 2026
- Windows availability
- The current download is version 0.9.2, and the maker says the program has not changed since 2008; the page reports it worked for the maker on Windows 10 in June 2023.checked 2 Oct 2026
The company
- Maker
- The site identifies Prof. Dr. Edmund Weitz as the maker and lists his address at HAW Hamburg in Hamburg, Germany.checked 2 Oct 2026
Money
- Regex explanation
- It tries to describe a regular expression in plain English and can display a graphical representation of its parse tree.checked 2 Oct 2026
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