Return a valid or invalid parser result without evaluating any expression or statement.
Submit the example or replace it with your own input. Source is parsed but never executed.
Explicit static behavior
Syntax validity answers whether the selected script, module, or unambiguous grammar can be parsed. It does not prove runtime correctness.
Syntax validity answers whether the selected script, module, or unambiguous grammar can be parsed. It does not prove runtime correctness.
Invalid syntax is returned as a structured result, while resource-limit failures remain hard errors.
Tool Swim parses source as standard ECMAScript inside a disposable Web Worker with a 2,000 ms deadline. It never calls eval, Function, imported modules, or user code.
Source and results stay in the current browser tab. The public tool makes no API request, stores no preset, and does not require an account or telemetry.
