RegexStudio vs Retest
RegexStudio
regexstudio.comRetest
github.comSide by side
| Figure | RegexStudio | Retest |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Linux | — | Yes |
| Plans published | 0 | 1 |
| Spec score · Regular Expression Testers | 7.1 (#16) | 7.6 (#10) |
| Purpose | RegexStudio is a workbench for writing, understanding, debugging, and sharing regular expressions. | Retest is a terminal regular expression tester intended as a simple, quick utility for developing regular expressions. |
| Support | The opened maker pages do not state a support channel or service level. | The maintainer invites questions by email and asks users to include “retest” in the subject line. |
Plans
In their own words
RegexStudio
RegexStudio is a free, open-source web workbench for testing and debugging JavaScript and PCRE2 regular expressions. Native JavaScript and PCRE2 10.47 through WebAssembly are listed as execution engines. Live results show matches and capture groups, while a step-through debugger records execution details. Railroad diagrams can be edited, and views cover explanations, tests, replacements, code generation, and abstract syntax trees. Test cases can check match status, counts, text, ranges, captures, and replacement output. Learning materials include interactive tutorials, practice mode, challenges, a pattern library, and a quick reference. Tutorials cover fundamentals and practical patterns, while noting that syntax varies among regex languages. Generated snippets target JavaScript/TypeScript, Python, Java, Go, Rust, C# (.NET), PHP, Ruby, Swift, and Kotlin. The interface, tutorials, and challenges support English, Simplified Chinese, and Japanese. Share links encode expressions, flags, test text, and replacements. PCRE2 workers have a two-second budget; debugger recording allows 2,000 checkpoints and 50,000 capture slots.
Retest
Retest is a free, open-source terminal utility for developing and checking regular expressions on Linux. A subject string can be supplied as an argument or piped through standard input, so it can fit into shell workflows. Retest finds all non-crossing matches and highlights nested capture groups in colors distinct from the whole match. An optional formatted list shows match order and string indexes. Release 0.2.2 added a flag for reading the subject from a file. The project provides Linux release binaries, including a 64-bit Debian installer listed for release 0.2.2. Its README describes compiling from source with Cargo and installing through a Makefile. The source code and documentation are licensed under Apache License 2.0. The project presents Retest as a terminal-based alternative to regex101, for developers building and checking patterns. No paid plans or usage limits are listed.