Regex Tester for Mac
A native Mac regex tester with two views in one tool: live match highlighting as you type, and an AST explainer that breaks your pattern into a labeled parse tree. Test a regex and understand it without leaving the app.
What it does
The Regex Tester has two panes. The tester pane takes a pattern and a block of test text and highlights every match in real time as you type — groups are highlighted separately with distinct colors, and the match count and group captures are listed below. Flags (case-insensitive, multiline, dotAll) are toggleable without editing the pattern string. The AST explainer pane takes the same pattern and renders it as a parse tree: each component of the regex — literal characters, quantifiers, character classes, groups, anchors — is labeled in plain language, and you can step through the non-deterministic finite automaton (NFA) trace line by line to see exactly how the engine evaluates your pattern against input. Both panes are part of the same tool; there is no separate tool for the explainer.
Why use Bench's regex tester
Browser-based regex tools are fast to reach but fragile as a workflow — closing the tab loses the pattern, and most don't offer structural explanations alongside live testing. Bench keeps the pattern and test text in a native window that survives across app switches. The AST explainer is the differentiating feature: rather than trial-and-error tweaks, you can read exactly which sub-expression is failing and why, which shortens debugging time considerably for complex patterns.
- Native Mac app. SwiftUI, single window, instant launch.
- Offline. No network calls. Patterns and test text stay on your Mac.
- No tracking. No analytics, no telemetry, no third-party SDKs.
- One-time purchase. $19 once, year of updates included, $9 optional renewal — no subscription.
Paste it. Bench picks the tool.
Smart Detection reads your clipboard locally and routes you to the Regex Tester when it sees something like:
^[\w.-]+@[\w.-]+\.[a-zA-Z]{2,}$
The detection runs entirely on your Mac as a rule-based heuristic — it checks for regex metacharacter patterns in the clipboard content. Nothing is uploaded.
Related tools in Bench
Regex Tester ships inside Bench, alongside 17 other developer tools. $19 one-time, year of updates included.
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