Regex Tester

Test regular expressions in real time with syntax highlighting and match group visualization.

All processing happens in your browser. Your data never leaves your device.

Regular Expression

Test String

Matches4 matches

#1"Hello"index 0–5

group 1: Hello

#2"World"index 6–11

group 1: World

#3"Hello"index 13–18

group 1: Hello

#4"Developer"index 19–28

group 1: Developer

How to Use Regex Tester

1Paste or type your input in the left panel.
2Click Process or use the keyboard shortcut ⌘↵.
3View the result in the output panel. Use Copy to copy to clipboard or Download to save as a file.

This tool processes data locally in your browser. Nothing is sent to external servers.

Example input

# Example for Regex Tester
# Paste your content in the input panel above to get started.

JavaScript regex is supported, which covers most common use cases.

Yes, all capture groups are highlighted and listed separately.

Global (g), case-insensitive (i), multiline (m), dotall (s), and unicode (u) flags are supported.

Yes, the start and end index of each match is shown.

Yes, the test string supports multiline input with the multiline flag.