gchq/CyberChef · error · OperationError

Unrecognized capitalization scope

Error message

Unrecognized capitalization scope

What it means

Thrown by CyberChef's 'To Upper case' operation when the first argument (scope) is not one of the recognised values 'All', 'Word', 'Sentence', or 'Paragraph'. The scope string indexes a regex lookup object; an unknown key yields undefined and this guard fires. In the browser UI the value comes from a fixed dropdown so this is only reachable via the Node API or a hand-built recipe.

Source

Thrown at src/core/operations/ToUpperCase.mjs:58

    run(input, args) {
        if (!args || args.length === 0) {
            throw new OperationError("No capitalization scope was provided.");
        }

        const scope = args[0];

        if (scope === "All") {
            return input.toUpperCase();
        }

        const scopeRegex = {
            "Word": /(\b\w)/gi,
            "Sentence": /(?:\.|^)\s*(\b\w)/gi,
            "Paragraph": /(?:\n|^)\s*(\b\w)/gi
        }[scope];

        if (scopeRegex === undefined) {
            throw new OperationError("Unrecognized capitalization scope");
        }

        // Use the regex to capitalize the input
        return input.replace(scopeRegex, function(m) {
            return m.toUpperCase();
        });
    }

    /**
     * Highlight To Upper case
     *
     * @param {Object[]} pos
     * @param {number} pos[].start
     * @param {number} pos[].end
     * @param {Object[]} args
     * @returns {Object[]} pos
     */
    highlight(pos, args) {

View on GitHub (pinned to 4290ea7539)

Solutions

1. Set the scope argument to one of the exact strings: 'All', 'Word', 'Sentence', or 'Paragraph'.
2. If building a recipe programmatically, read the allowed values from the operation's args[0].value array rather than hardcoding.
3. If you want whole-string uppercasing, use scope 'All'.

Example fix

// before
chef.toUpperCase("hello", ["all"]);
// after
chef.toUpperCase("hello", ["All"]);

const SCOPES = ["All", "Word", "Sentence", "Paragraph"];
if (!SCOPES.includes(scope)) {
  throw new Error(`Invalid scope '${scope}'. Expected one of: ${SCOPES.join(", ")}`);
}

function isValidScope(s) { return ["All","Word","Sentence","Paragraph"].includes(s); }

When it happens

Trigger: Invoking ToUpperCase.run(input, [scope]) with a scope value that is not exactly 'All', 'Word', 'Sentence', or 'Paragraph' (case-sensitive). For example passing ['all'], ['Words'], undefined, or an empty array after the args.length===0 guard was bypassed.

Common situations: Calling the operation programmatically through the CyberChef Node API with a recipe whose scope arg was copied from a different version, or passing a lowercased/localised scope label. Also seen when constructing recipes dynamically and forgetting the scope element.

Related errors

• Rotor ${i} must be provided.
• Unrecognised unit
• ${this.name} length cannot exceed ${this.maxLength}.
• Invalid Public Key
• Error: Invalid output format

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/2fdd94bd1c58dd13. Report an issue: GitHub.