New in Toolbox 1.1
Test regular expressions on your Mac
Type a pattern and Regex Tester highlights every match in your text as you go, listing each match with its capture groups, numbered and named. Toggle the i, m, s and x flags and preview a replacement that uses $1 or ${name}. It uses ICU regular expressions, the syntax of NSRegularExpression, and stops a runaway pattern after two seconds instead of freezing.
How to use Regex Tester
Open Regex Tester and paste the text to search, or drop a text file.
Type your pattern between the slashes. Matches are highlighted as you type, and a mistake in the pattern is explained.
Turn on Ignore Case, Multiline, Dot Matches Newline or Extended as needed.
Type a replacement such as $2/$1 or ${year} to preview the result, then click Copy Result or Copy Matches.
Questions about Regex Tester
Which regex flavor does it use?
ICU, the engine behind NSRegularExpression on Apple platforms. For everyday patterns it behaves much like PCRE and JavaScript, with named groups, lookahead and lookbehind, Unicode properties and \Q…\E quoting.
How do I use capture groups in the replacement?
Use $1 to $99 for numbered groups, ${name} for named ones and $0 for the whole match. Write $$ for a dollar sign and \n for a line break.
What happens if a pattern backtracks too much?
Toolbox stops after two seconds, keeps the matches found so far and suggests looking for nested quantifiers like (a+)+, so a bad pattern never hangs the app.
Is it free, and is my text uploaded?
Toolbox is a paid app, and one purchase includes every tool, with no subscription or account. Patterns run on your Mac, so logs and data you test against never leave it.
Related tools
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- JSON FormatterPretty-print, minify and validate JSON, with the line and column of any mistake.
- Batch RenameRename many files at once with find and replace, numbering, dates or case changes.
- Timestamp ConverterTurn Unix timestamps into dates and back, in seconds, milliseconds or microseconds, in any time zone.
