RegEx Tester
RegEx Tester is a free, open-source web tool for checking regular-expression patterns against sample text.
What RegEx Tester is
RegEx Tester is a free, open-source web tool for checking regular-expression patterns against sample text. Enter a pattern and test text in separate fields, then view the output in its Result area. The tool supports .NET, Node.js, Python and Java regex flavors. ShowCaptures displays capture information, while Replace and To fields support replacement work. RegEx Tester runs online through its GitHub Pages site, with no desktop platform listed. The maker links to source code hosted by the RegExTester GitHub organization and reports 1.5k users with 2k test sessions in 2021. The live interface lists engine options but does not state usage quotas or trial terms.
Good
- Free plan available
- Supports four regex flavors
- Many regex engine options
- Shows captures and results
- Offers replacement fields
Watch out
- Web platform only
- No usage quota stated
- No trial details listed
Who it suits
It suits developers and other users who need to check regex behavior in a browser. It is relevant when working with the listed .NET, Node.js, Python or Java flavors.
Verdict
RegEx Tester provides focused browser-based pattern testing with several regex flavors and detailed options. Its free access and replacement controls suit quick checks without desktop installation.
The facts
Each one read from RegEx Tester's own pages, with the date it was checked.
What it does
- Availability
- The tool is available online at its GitHub Pages site.checked 8 Oct 2026
- Capture display
- The interface includes a ShowCaptures option.checked 8 Oct 2026
- Integrations
- The opened official pages do not describe integrations.checked 8 Oct 2026
- Notable limits
- The live interface lists regex engine options but does not state pricing, usage quotas, or a trial.checked 8 Oct 2026
- Pattern and text inputs
- The tester provides fields for a regular-expression pattern and test text.checked 8 Oct 2026
- Purpose
- RegEx Tester is a free, open-source tool for testing regular expressions online.checked 8 Oct 2026
- Regex options
- Available options include IgnoreCase, Multiline, ExplicitCapture, Compiled, Singleline, IgnorePatternWhitespace, RightToLeft, ECMAScript, CultureInvariant, and NonBacktracking.checked 8 Oct 2026
- Replace
- The interface includes a Replace To input.checked 8 Oct 2026
- Replacement
- The interface includes a Replace field and a To field.checked 8 Oct 2026
- Results
- The interface has a Result area for the test output.checked 8 Oct 2026
- Security and compliance
- The opened official pages do not state security or compliance claims.checked 8 Oct 2026
- Source code
- The maker links to source code hosted under the RegExTester GitHub organization.checked 8 Oct 2026
- Support contact
- The GitHub organization lists [email protected] as its contact email.checked 8 Oct 2026
- Usage reported
- The maker says the tool served 1.5k users with 2k test sessions in 2021.checked 8 Oct 2026
The company
- Usage noted by maker
- The maker says the tool served 1.5k users with 2k test sessions in 2021.checked 8 Oct 2026
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