Regex Crossword icon

Regex Crossword

CuSO4Deposit
Word Game Puzzle
Version
0.2.1
Size
1.1 MB
Requires
Android API 24+
4.8 / 5 · 2,492 ratings 15,493 downloads

Updated Oct 4, 2026

Quick answer

Offline regex-crossword puzzles in hexagon and rectangle grids.

Regex Crossword is an offline puzzle game. Every line of the grid is a regular expression; fill the cells so that each line, read in its own direction, matches its clue exactly (a whole-string match).

Features:

* Three difficulties: Easy (rectangle 5x5), Medium and Hard (hexagon). Puzzles are generated on your device from a seed, so the number of levels is unlimited. * The hexagonal board has three colour-coded reading directions (X, Y, Z); the rectangle board uses rows and columns. Each clue shows its reading direction and start cell. * Tap a cell and use the on-screen keyboard. Pencil-mark notes, per-cell hints, "givens" (letters a clue writes down literally), undo/redo, and a per-level timer. * Progress is saved automatically for every level.

Hard levels are pre-generated with a solver so that their answer is unique.

No accounts. No ads. No network access. No permissions.

Regex Crossword is free software under the MIT licence. The hexagonal "A Regular Crossword" form was popularised by Dan Gulotta (based on an idea by Palmer Mebane) in MIT Mystery Hunt 2013. This app is an independent implementation and includes neither the original puzzle nor its text.

Source code: https://github.com/CuSO4Deposit/regex-crossword

Screenshots

Regex Crossword screenshot 1
Regex Crossword screenshot 2
Regex Crossword screenshot 3

What’s new

Offline regex-crossword puzzles for Android.

* Easy (rectangle 5x5) and Medium / Hard (hexagon) difficulties.
* Puzzles generated on device from a seed; Hard levels pre-generated with the
solver so their answer is unique.
* Notes, per-cell hint, givens, undo/redo and a per-level timer.
* Progress saved automatically. No accounts, ads, network access or permissions.
* Release APK keeps R8 shrinking (smaller download) and is reproducible, so
F-Droid ships the developer's own signature.

How to install

  1. Download the APK from the button at the top of this page.
  2. Allow “Install unknown apps” for your browser or file manager only, not for every app.
  3. Open the downloaded file and confirm the installation.
  4. If installation fails with “App not installed,” remove an earlier build of the same app first. A signature conflict is the usual cause.

Data safety

  • Every file is checked against its published SHA-256 before it is listed.
  • Files are scanned for malware on every update.
  • The permissions each app requests are listed on its own page.
  • Read the full safety policy for how we test, flag, and delist files.

Frequently asked questions

What is Regex Crossword?
Offline regex-crossword puzzles in hexagon and rectangle grids.
Who develops Regex Crossword?
Regex Crossword is developed by CuSO4Deposit.
Which Android version does Regex Crossword require?
Regex Crossword requires Android API 24 or later.
What is the current version of Regex Crossword?
The synchronized F-Droid version is 0.2.1.
Which license does Regex Crossword use?
The signed F-Droid metadata lists MIT.
Where is the source code for Regex Crossword?
https://github.com/CuSO4Deposit/regex-crossword

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