How to use the Regex Tester tool
- Open the tool — tap the button above; the Regex Tester tool opens instantly, ready to use.
- Add your input — type your pattern and test text - results update live.
- Download the result — hit Process and your result is ready in seconds, straight from your browser.
Why use PDFPremium.pro?
Every developer knows the loop: write a regex, wonder why it does not match, add a backslash, wonder again. This tester ends the guessing - type the pattern and flags, paste the test text, and every match highlights live as you type, with match count and capture groups shown below. Invalid pattern? A clear error message instead of silence. Runs entirely locally, so testing patterns against real data (logs, customer lists) is safe. As with every tool here, it runs entirely inside your browser - no uploads, no sign-ups, no watermarks.
Frequently asked questions
What flags are supported?
All JavaScript flags - g (all matches), i (ignore case), m (multiline), s (dotall) and more; type them in the flags box and results update instantly.
Is this tool really free?
Yes — completely free with no hidden limits, watermarks, or sign-up. The site is supported by light advertising.
Are my files uploaded to a server?
No. Everything runs inside your browser using JavaScript — your files never leave your device, ever.