JavaScript / Node lint: POST {code}, get the bugs back with line numbers. Syntax errors come from the real V8 parser (compile-only — code is never executed), plus deterministic checks: loose == coercion, assignment in conditions, comparisons with NaN, const reassignment (runtime TypeError), var pitfalls, unused variables, leftover console.log. Handles ESM imports, template literals, regex. No AI. Max 128 KB.

Payment Options