gchq/CyberChef · error · OperationError

Width must be no more than ${MAX_WIDTH}

Error message

Width must be no more than ${MAX_WIDTH}

What it means

To Hexdump caps the line width at MAX_WIDTH to keep the rendered output within practical bounds. The guard throws when the length argument exceeds that constant, after the positive-integer check has already passed.

Source

Thrown at src/core/operations/ToHexdump.mjs:70

            }
        ];
    }

    /**
     * @param {ArrayBuffer} input
     * @param {Object[]} args
     * @returns {string}
     */
    run(input, args) {
        const data = new Uint8Array(input);
        const [length, upperCase, includeFinalLength, unixFormat] = args;
        const padding = 2;

        if (length < 1 || Math.round(length) !== length)
            throw new OperationError("Width must be a positive integer");

        if (length > MAX_WIDTH)
            throw new OperationError(`Width must be no more than ${MAX_WIDTH}`);

        const lines = [];
        for (let i = 0; i < data.length; i += length) {
            let lineNo = Utils.hex(i, 8);

            const buff = data.slice(i, i+length);
            const hex = [];
            buff.forEach(b => hex.push(Utils.hex(b, padding)));
            let hexStr = hex.join(" ").padEnd(length*(padding+1), " ");

            const ascii = Utils.printable(Utils.byteArrayToChars(buff), false, unixFormat);
            const asciiStr = ascii.padEnd(buff.length, " ");

            if (upperCase) {
                hexStr = hexStr.toUpperCase();
                lineNo = lineNo.toUpperCase();
            }

View on GitHub (pinned to 4290ea7539)

Solutions

1. Reduce the length argument to MAX_WIDTH or below (typically use 16 or 32).
2. Check the module's MAX_WIDTH constant for the exact bound.
3. Split large data across multiple operations if wider rows are truly needed.

Example fix

// before: args[0] (length) = 999 (> MAX_WIDTH) -> throws
// after:  args[0] (length) = 16                 -> within cap, passes

if (length > MAX_WIDTH) {
  throw new Error(`Hexdump width must be <= ${MAX_WIDTH}`);
}

const withinMaxWidth = w => Number.isInteger(w) && w >= 1 && w <= MAX_WIDTH;

try { toHexdump(input, [length, ...rest]); }
catch (e) { if (/no more than/.test(e.message)) { length = MAX_WIDTH; } else throw e; }

When it happens

Trigger: Setting the length argument to a value greater than MAX_WIDTH (defined at the top of the module).

Common situations: Requesting an extremely wide row for compactness; misreading the cap; copying a config from a fork with a different MAX_WIDTH.

Related errors

• Width must be a positive integer
• Byte length must be a positive integer
• L must be non-negative
• L too large (maximum length for ${args[2]} is ${255 * HashLe
• Invalid IV length: ${iv.length} bytes TEA uses an IV length

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/ace92cc9f129cfe8. Report an issue: GitHub.