The fastest way to reach us is email: hello@nxtolerance.com.

What to write about

Correctness bugs (highest priority). If the tool reports a match your browser disagrees with — a wrong index range, a group that highlights the wrong span, a replace preview that differs from String.replace() — send us the pattern, the flags, the test string, and which browser/engine showed the difference. The tester deliberately mirrors your browser’s RegExp rather than implementing its own, so a real divergence is genuinely interesting and we want it.

Explain-mode mistakes. The explainer tokenizes patterns by hand — if it describes a token wrong (a class parsed incorrectly, a quantifier attached to the wrong atom, a lookaround mislabeled), quote the pattern and the line it produced. Same for the backtracking warning: if it fired on a pattern that can’t backtrack badly, or missed an obvious (x|xy)+ bomb, we want the example.

Library patterns. The library deliberately ships rough patterns with written caveats rather than “perfect” ones. If you think a library entry’s caveat is incomplete — a case where the email pattern misleads that the note doesn’t already cover — tell us what it accepted or rejected and why it mattered in your use. We’re not looking for longer regexes; we’re looking for more honest notes.

Corrections to the guides. If something in the cheat sheet, the email trap article or the backtracking explainer is wrong or out of date, quote the line and tell us the right behavior. Include the page URL.

Everything else. Broken pages, accessibility issues, partnership requests.

What to expect

We’re a small team and read every message. Reports with a reproduction case (“/(\d+)x/ on 12x34x shows group 1 at the wrong index”) are usually answered within a few days; general feedback may take longer. No ticket system, no automated replies — a person reads and answers your email.