URLSearchParams: size property

Note: This feature is available in Web Workers.

The size read-only property of the URLSearchParams interface indicates the total number of search parameter entries.


A number indicating the total number of search parameter entries in the URLSearchParams object.


Getting the amount of search parameter entries

You can get the total number of search parameter entries like so:

const searchParams = new URLSearchParams("c=4&a=2&b=3&a=1");
searchParams.size; // 4

Note how the a parameter is given twice, but size returns the number of all given entries (4) and not 3. To get the amount of unique keys, you can use a Set, for example:

[...new Set(searchParams.keys())].length; // 3

Checking if search parameters exist

The size property is useful for checking whether there are any search parameters at all:

const url = new URL("https://example.com?foo=1&bar=2");

if (url.searchParams.size) {
  console.log("URL has search parameters!");


URL Standard
# dom-urlsearchparams-size

Browser compatibility

BCD tables only load in the browser

See also