API Reference > frontend-devtools > Utilities > parseBoolean parseBoolean Function Beta Parses a string case-insensitively returning true for "ON" or "TRUE", false for "OFF" or "FALSE" and undefined otherwise. Used by various tools which take such arguments. parseBoolean(arg: undefined | string): boolean | undefined Parameter Type Description arg undefined | string Returns - boolean | undefined Defined in frontend-devtools/src/tools/parseBoolean.ts Line 14 Last Updated: 11 June, 2024