Retest
What it is
Retest is a free, open source terminal utility for developing and checking regular expressions on Linux. Supply the subject text as an argument or send it through standard input, so it can fit into shell pipelines. Retest finds all non-crossing matches in the text and distinguishes nested capture groups from the whole match with colors. An optional formatted list shows matches in order and gives their string indexes. Release 0.2.2 added a flag for reading the subject from a file. The project offers Linux binaries, including a 64-bit Debian installer listed for that release. The README also describes compiling the program with Cargo and installing it through a Makefile. Retest's source code and documentation are licensed under Apache License 2.0. The project presents it as a terminal-based alternative to regex101, aimed at developers who want to build and inspect patterns from the command line. No paid plans or usage limits are listed.
For and against
For
- Free and open source
- Accepts subject text through arguments or standard input
- Highlights nested capture groups in distinct colors
- Optional list shows match order and string indexes
- Linux binaries and source build instructions are provided
Against
- Listed platform is Linux
- The project is terminal based
The verdict
Retest focuses on pattern development and match inspection in a terminal, with file input and shell piping available. Its Apache License 2.0 and Linux release binaries make the distribution details clear.
Who it suits
Retest suits developers who want to create and inspect regular expressions in a Linux terminal. Its standard input support is useful when working with shell pipes.
Plans and prices
Free
No paid plans or usage limits are listed
Read 9 Oct 2026 · github.com
On the record
- Build
- The README describes compiling from source with Cargo and installing through a Makefile.github.com · read 4 Oct 2026
- Feature requests
- Users can suggest features by opening a GitHub issue or emailing the maintainer.github.com · read 9 Oct 2026
- Feedback
- Users can suggest features by opening a GitHub issue or emailing the maintainer.github.com · read 4 Oct 2026
- File input
- The v0.2.2 release added a command flag to read a subject directly from a file.github.com · read 9 Oct 2026
- Highlighting
- It highlights nested capture groups in colors distinct from the whole match.github.com · read 4 Oct 2026
- Input
- A subject string can be piped to Retest through standard input or supplied as an argument.github.com · read 9 Oct 2026
- Installation
- The project provides Linux release binaries and instructions for compiling and installing from source with Cargo or Make.github.com · read 9 Oct 2026
- Integration
- Retest accepts input through standard input, so it can be used with shell pipes.github.com · read 9 Oct 2026
- Intended users
- The README presents Retest as a developer utility for building and checking regular expressions in a terminal.github.com · read 9 Oct 2026
- License
- The source code and documentation are licensed under Apache License 2.0.github.com · read 9 Oct 2026
- Linux downloads
- The project provides Linux binaries for releases, and release 0.2.2 also lists a 64-bit Debian installer package.github.com · read 4 Oct 2026
- Matches
- It finds all non-crossing matches in the subject string.github.com · read 4 Oct 2026
- Matching
- Retest finds all non-crossing matches in the subject string.github.com · read 9 Oct 2026
- Match list
- An optional formatted list shows match order and string indexes.github.com · read 9 Oct 2026
- Nested highlighting
- Capture groups and subgroups are highlighted in different colors from the whole match.github.com · read 9 Oct 2026
- Piping
- It can read the subject string to match from standard input.github.com · read 4 Oct 2026
- Purpose
- Retest is a terminal regular expression tester intended as a simple, quick utility for developing regular expressions.github.com · read 4 Oct 2026
- Support
- The maintainer invites questions by email and asks users to include “retest” in the subject line.github.com · read 9 Oct 2026
