Use Regex Tester
- Enter or configure the source values.
- Choose the relevant mode and run the action.
- Review the result before copying or downloading it.
Regex Tester with Safe Worker
Test ECMAScript regular expressions, flags, captures, and match ranges in a timeout-protected local worker.
Inputs and results stay in browser memory in this tab. Nothing is uploaded, logged, saved, or added to the URL. Evaluation runs in a terminable local worker.
Enter text and choose an action.
Inspect ECMAScript matches and capture groups without allowing a pathological pattern to hold the main interface.
How OpenFileTools processes it
Local processing, explicit choices.
OpenFileTools performs this developer transformation locally in the browser after an explicit action.
Questions, answered.
Is any input uploaded?
No. Input and results stay in memory in the current browser tab.
What should I verify?
Evaluation is limited by pattern size, text size, match count, and a worker timeout.