A visual regex builder for macOS that runs your pattern on the real engine.
RegexPilot's application source is proprietary and closed-source — it isn't in this repo. This repository is the app's public face: the issue tracker, and the two things that genuinely are open — bundled color themes and translations — published as plain data under an MIT license (see License below).
If you're looking for the app itself: download it,
get it from the Mac App Store,
or brew install --cask kristofp/regexpilot/regexpilot.
RegexPilot turns a regular expression into a railroad diagram you can edit directly — drag blocks from a palette, connect them on a track, and read a plain-English explanation of every part as you work.
Most regex tools test your pattern with JavaScript and hope it behaves the same in the language you actually ship. RegexPilot bundles native engines for all 21 supported flavors and runs the pattern through the real interpreter for your target language, rather than an approximation:
| Flavor | Engine |
|---|---|
| JavaScript / TypeScript | JavaScriptCore (the engine Safari runs), with regress (a pure-Rust ES2018 engine) as an automatic fallback if the system framework is unreachable |
| Python | CPython (re and regex) |
| Java, Kotlin, Scala, Groovy, Clojure (JVM family) | java.util.regex via GraalVM native-image |
| Ruby | Onigmo, statically linked |
| C# | .NET |
| PHP | PCRE2 via static-php-cli |
| Go | Go's stdlib regexp (RE2, no backtracking) |
| Rust | the regex crate (RE2-family, default) or fancy-regex (backtracking, selectable — for lookaround/backreferences) |
| Swift | NSRegularExpression (ICU regex) |
| PostgreSQL | PostgreSQL's own Spencer ARE engine, statically linked |
| MySQL | ICU |
| Perl | Bundled microperl |
| Dart | Dart's own RegExp (V8-derived Irregexp) via the user's system Dart SDK, with a JavaScriptCore-based approximation as fallback if no SDK is installed |
| Elixir | Erlang's :re (PCRE2-based) via the user's system Elixir/Erlang install, with a PCRE2 approximation as fallback if it isn't installed |
| R | base R's TRE engine by default (POSIX, no lookaround), or PCRE2 (perl=TRUE) when selected — via the user's system R install, with a PCRE2 approximation as fallback if it isn't installed |
| Shell | Bundled TRE, statically linked (POSIX BRE/ERE) — not BSD or GNU grep/sed/awk, which the sandboxed app cannot execute |
21 flavors in total: JavaScript, TypeScript, Python, Java, C#, PHP, Go, Rust, Swift, Kotlin, Ruby, PostgreSQL, MySQL, Shell, R, Dart, Scala, Perl, Elixir, Groovy, Clojure.
- AI-assisted generation — describe a pattern in plain English and get a working draft. Bring your own API key (OpenAI, Claude, Gemini, DeepSeek, Qwen, Mistral, Groq, OpenRouter, xAI), point it at any custom OpenAI-compatible endpoint, or run fully offline with LM Studio, Ollama, llama.cpp or LocalAI.
- Voice dictation — on-device, via a bundled Whisper model, 100 languages.
- Live testing — paste sample text; matches and capture groups highlight as you type, in both match and replace modes.
- Pattern library — curated patterns plus folders, tags, search, import and export.
- Code generation — copy your pattern as ready-to-paste code across all 21 supported flavors.
- Editor integration — the VS Code extension opens a selected regex literal in the app and can sync edits back to your file.
- Color themes — a bundled set of community-style themes (Dracula, Catppuccin, Nord, Tokyo Night, Gruvbox, Solarized, GitHub, Rosé Pine, One, Ayu, Everforest, Kanagawa, Night Owl, Tomorrow, plus the default), all free, with import/export for your own — see Themes below.
- Localization — English, Dutch, French, German in the shipping app; see Translations below for how the strings behind that are published and how to contribute one.
- Privacy by construction — no accounts, no telemetry, no analytics. Nothing is reported to a server on its own; creating a share link is always a deliberate action, never automatic.
RegexPilot is a one-time purchase, not a subscription.
Free, forever:
- The full visual builder — canvas, drag-and-drop, inspector
- JavaScript and TypeScript flavors only
- Match/replace testing
- Pattern library (local, capped at 20 patterns)
- Every bundled theme, plus theme import/export
- Export to JSON
€19 one-time license (v2 owners get a 50% upgrade discount) unlocks:
- All 21 flavors, with their authentic native engines
- AI-assisted regex generation (bring your own API key — AI is not available on the free tier, with or without your own key)
- Unlimited pattern library
- All export formats, including code generation, PNG/SVG, SnippetsLab and VS Code
30-day free trial of everything above starts the first time you select a non-JavaScript flavor — no signup, no credit card. After the trial, the app reverts to the free tier; your non-JS library patterns stay visible but become read-only until you unlock.
There is no hosted-AI subscription and no free-tier AI: AI generation is entirely bring-your-own-key, and it's one of the things the trial/license unlocks alongside the other 19 flavors.
RegexPilot reports nothing to a server on its own. There's no telemetry and no analytics. The only network requests the app makes are ones you explicitly trigger: an AI call using your own API key, or creating a share link. License validation happens locally against a signed token.
Every release is published on this repo's Releases page, built and uploaded by the same release run that ships the app:
-
App (DMG): RegexPilot-universal.dmg — universal binary (Apple Silicon + Intel), signed and notarized.
-
All themes: regexpilot-themes.zip
-
All translations: regexpilot-translations.zip
-
Mac App Store: apps.apple.com/us/app/regexpilot — same app; Apple handles payment and updates.
-
Homebrew:
brew install --cask kristofp/regexpilot/regexpilot
Requirements: macOS 14 (Sonoma) or later.
Select a regex in your editor and send it to the app — right-click Open in RegexPilot, or use the CodeLens shown above a detected regex literal. Pick Edit in RegexPilot instead and the two stay in sync: rebuild the pattern on the canvas and the edit lands back in your file.
Install from the VS Code Marketplace (one-click install and auto-update).
This repo hosts the public issue tracker. The app's source is private; this exists so bugs and feature requests are visible and trackable.
- Open a bug report
- Open a feature request
- Or start from the issue chooser
Please include your RegexPilot version (RegexPilot menu → About RegexPilot), macOS version, the regex flavor you were using (if relevant), and steps to reproduce. Search existing issues first. For urgent account or billing issues, email support@regexpilot.com instead of filing an issue.
themes/ holds every bundled color theme as a ready-to-import
JSON file — <id>.json, one per theme, generated straight from the app's
own theme catalog by the same serializer "Settings → Appearance →
Export Theme…" uses, so the file you'd get from the app and the file published here
are the same shape. See themes/README.md for the full
list. To use one, download a file and import it via Settings → Appearance →
"Import Theme…".
translations/ holds the app's UI strings for every
shipping locale (English is the reference), plus a generated coverage table
and a short guide for contributing a fix or a new translation — see
translations/README.md. Short version:
edit the JSON, keep {placeholder} tokens intact, and open a pull request
or an issue with your changes attached. Contributions here are reviewed and
merged into the app's bundled catalog by hand before they ship in a
release — this repo isn't wired directly into the live app.
The RegexPilot application (this repo does not contain its source) is proprietary, closed-source software.
The contents of themes/ and translations/
in this repository are licensed under the MIT License — see
LICENSE at the repository root, and the copy inside each of
those two directories.