In Google Sheets, the ISURL(value) function is used to determine whether a given value is a valid URL (Uniform Resource Locator) or not.

It checks whether the value follows the basic syntax rules of a URL.

The ISURL function takes one argument, which is the value you want to test. It can be a cell reference, a text string, or a formula that returns a URL or a text string.

The function returns TRUE if the value is a valid URL and FALSE if it is not.

Here's an example of how to use the ISURL function in Google Sheets:

Type a URL or a text string into cell A1, for example:

A1: https://www.example.com

In another cell, use the ISURL function to check if the value in A1 is a valid URL

B1: =ISURL(A1)

The cell B1 will display TRUE if the value in A1 is a valid URL, or FALSE if it is not.

Keep in mind that the ISURL function only checks for the basic syntax of a URL. It does not verify whether the URL actually exists or if the link is accessible.

It is useful for basic validation but may not catch all possible edge cases.