Clear all cookies

Expire every cookie that JavaScript can see on the current path.

JavaScriptBrowser · DOM Version 1.0.0 · MIT · .md

function clearCookies() {
  for (const cookie of document.cookie.split(';')) {
    const name = cookie.split('=')[0].trim();
    if (name) document.cookie = `${name}=; Max-Age=0; path=/`;
  }
}

Usage

document.cookie = 'theme=dark; path=/';
document.cookie = 'lang=pt-BR; path=/';
clearCookies();
document.cookie; // → ''

Lines marked → were executed in headless Chromium against the markup above, and each result was compared with the value shown. Lines marked e.g. are illustrative.

Know the limits

• HttpOnly cookies, such as most session cookies, are invisible to JavaScript; only the server can clear them with Set-Cookie.
• A cookie set with another Path or Domain must be expired with the same attributes.
• The original set expires to the current time; Max-Age=0 expires immediately without relying on the client clock.

The function above is the code the usage lines run. It does not validate its arguments; add checks where it receives untrusted input.

Keep exploring

• Convert Celsius to Fahrenheit — Apply the temperature conversion without rounding the result.
• Convert hex to RGB — Expand #rgb if needed and read the red, green and blue channels.
• Convert URL parameters to object — Read a query string into an object; repeated keys become arrays.