Expressions1.3.10

Type a regular-expression pattern into Expressions and see its matches appear immediately in sample text. This MacOS Developer Tools app provides a focused workspace for experimenting with regex instead of keeping that work in browser tabs. Its live preview updates as you edit either the pattern or the test text, making it easy to verify changes as you work.

Syntax highlighting improves pattern readability, while the built-in reference sheet opens with Command-R when you need a reminder of regex syntax. An expression library stores reusable expressions, examples, and patterns for later use. Expressions highlights both matched text groups and their corresponding pattern groups, with Command-Shift-] and Command-Shift-[ switching between groups. Complex patterns can be split across lines with the “Allow whitespaces and comments” option, and full-screen mode removes distractions during focused editing.

The app suits developers and other technical users who build, inspect, or learn regular expressions, particularly when testing Apple-framework-compatible patterns. It uses ICU regular expressions, the standard used by Apple frameworks, and keeps typed text and patterns on the Mac without collecting usage analytics or telemetry. Dark and light appearances, along with its minimal button-light interface, accommodate different working preferences.

Version 1.3.10 requires macOS 12 Monterey or later and runs on both Intel and Apple Silicon Macs. It is cataloged as freeware; purchases cover the current major version as one-time payments, while Setapp provides access through its subscription, and an Expressions 1 license includes 1.x updates. Since version 1.3.5, the license system has changed, so older license numbers require replacement with a new number available at no cost.