Regex Tester
Real-time regex testing with match highlighting, code generation, and pattern explanation
Regex Tester
Enter a regex pattern and test text to see real-time matches, capture groups, and more.
Ctrl+Enter to focus pattern input
Regex Tester & Debugger — Free Online Tool
Test and debug regular expressions in real time with inspectly.dev's Regex Tester. Write a pattern, paste test strings, and see all matches highlighted instantly — with named capture groups, match details, and code generation for JavaScript, Python, Go, and more.
Key Features
- Real-time match highlighting as you type the pattern
- Support for all standard flags: global, case-insensitive, multiline, dotAll
- Named and unnamed capture group extraction
- Match table showing all groups and their positions
- Substitution mode — preview replace() results
- Code generation for JavaScript, Python, PHP, Go, Java, and Ruby
- Common pattern library: email, URL, date, IP address, phone, and more
- 100% client-side using the browser's native RegExp engine
Common Use Cases
- Building and testing input validation patterns (email, phone, URL)
- Extracting data from log files using capture groups
- Prototyping search and replace operations before adding to code
- Learning regular expression syntax interactively
- Debugging regex patterns that aren't matching as expected
- Generating regex code snippets for multiple programming languages
Frequently Asked Questions
How do I test a regex pattern online?
Go to inspectly.dev/regex, enter your pattern in the Regex field, paste your test text below, and matches are highlighted in real time. Select flags (g, i, m) using the checkboxes next to the pattern input.
What regex engine does this tool use?
The tool uses the JavaScript RegExp engine built into your browser. This means it supports JavaScript regex syntax including lookaheads, lookbehinds (modern browsers), and named capture groups (?<name>...).
How do I extract capture groups from a regex match?
Add parentheses around the part of your pattern you want to capture — for example, (\d+) to capture digits. Named groups use the syntax (?<name>pattern). The match table below the editor shows each group's value.
Can I generate code from my regex pattern?
Yes. Once you have a working pattern, click the "Code" tab to get ready-to-use code snippets for JavaScript, Python, PHP, Go, Java, and Ruby — with the pattern, flags, and example usage included.