Validation/Since 1.38.0

isURL

Checks whether a value is a valid URL using the native URL constructor and allows only HTTP and HTTPS protocols.

isURL(value):boolean

Validation

The function first checks that the value is a string, trims it, and rejects empty strings. It then passes the value to the native URL constructor.

After parsing the URL, the function accepts only http: and https: protocols. Other valid URL protocols are rejected.

If the native URL constructor throws while parsing the value, the function catches the error and returns false.

The function is a TypeScript type guard. When it returns true, TypeScript narrows the value from unknown to string.

valueunknownrequired

The value to validate as a URL.

boolean

Returns true when the value can be parsed as a URL with an HTTP or HTTPS protocol; otherwise returns false.

HTTP URLs are accepted.

TypeScript

isURL("http://example.com");
// true

HTTPS URLs are accepted.

TypeScript

isURL("https://example.com/path?query=1");
// true

URLs using protocols other than HTTP or HTTPS are rejected.

TypeScript

isURL("ftp://example.com");
// false

isURL("mailto:test@example.com");
// false

Values that cannot be parsed by the native URL constructor are rejected.

TypeScript

isURL("not-a-url");
// false

isURL("example.com");
// false

Leading and trailing whitespace is removed before validation.

TypeScript

isURL("  https://example.com  ");
// true

Non-string values are rejected.

TypeScript

isURL(123);
// false

isURL(null);
// false

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