feathericons/feather · error · Error

The required `key` (icon name) parameter is missing.

Error message

The required `key` (icon name) parameter is missing.

What it means

feather.toSvg(name, attrs) (deprecated) requires an icon name string as its first argument; it is used to look up the icon in the internal icons map. When the argument is undefined, null, or an empty string, the library cannot proceed and throws. The method is deprecated in favor of feather.icons[name].toSvg().

Source

Thrown at src/to-svg.js:16

import icons from './icons';

/**
 * Create an SVG string.
 * @deprecated
 * @param {string} name
 * @param {Object} attrs
 * @returns {string}
 */
function toSvg(name, attrs = {}) {
  console.warn(
    'feather.toSvg() is deprecated. Please use feather.icons[name].toSvg() instead.',
  );

  if (!name) {
    throw new Error('The required `key` (icon name) parameter is missing.');
  }

  if (!icons[name]) {
    throw new Error(
      `No icon matching '${name}'. See the complete list of icons at https://feathericons.com`,
    );
  }

  return icons[name].toSvg(attrs);
}

export default toSvg;

View on GitHub (pinned to 3dc050d974)

Solutions

1. Pass a non-empty icon name string: feather.toSvg('circle').
2. Better, migrate to the non-deprecated API: feather.icons[name].toSvg(attrs).
3. Add a default value for the variable/prop that supplies the name.
4. Validate typeof name === 'string' && name before calling.

Example fix

// before
feather.toSvg(iconName); // iconName is undefined

// after
feather.icons['circle'].toSvg();

if (typeof name !== 'string' || name.length === 0) throw new Error('icon name is required');

const hasIconName = (v: unknown): v is string => typeof v === 'string' && v.trim().length > 0;

try {
  const svg = feather.icons[name].toSvg(attrs);
} catch (e) {
  if (e.message.includes('required `key`')) {
    // fall back to a default icon or surface a config error
  } else {
    throw e;
  }
}

When it happens

Trigger: Calling feather.toSvg() with no arguments, or with a variable that is undefined/null/'' at call time (e.g. a failed config lookup or a missing prop).

Common situations: Passing a dynamically computed icon name that ends up empty; a component prop with no default; migration code calling the old API with an unset variable.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• feather.toSvg() is deprecated. Please use feather.icons[name

AI-assisted analysis of feathericons/feather@3dc050d974 (2026-08-30). Data as JSON: /api/errors/6691b2c1c58fb566. Report an issue: GitHub.