Developer
Ready. All on your device.Regex Tester
Test JavaScript regular expressions locally, highlight matches and inspect capture groups or replacements.
Replacement preview
How to use Regex Tester
- Choose your plain text or paste text into the editor.
- Enter a pattern without slash delimiters, set flags and add test text. Live testing is optional.
- Inspect matches, named groups and UTF-16 positions, preview replacements or download a JSON report.
Process multiple files
Use a workflow to apply the same settings to each file.
Formats and requirements
- Input formats
- plain text
- Output
- JSON
- Availability
- Free in your browser and through the CLI
- Files per operation
- 1
- Browser file limit
- 128 KiB per file, 128 MiB total
What to expect
Tests JavaScript regular expressions locally with captures, named groups, UTF-16 positions and replacement. up to 128 MiB of text, 1000 matches and 128 MiB of output. Execution is time limited; the CLI requires Node.js.
Do my files leave my device?
No. Thanks to advanced file-processing technology, your files are processed directly on your device, inside your browser. OneKit does not receive your input files or results. Required public processing libraries may download when you first use the tool.
File privacy and local processing →