isUrl
function isUrl(value: unknown): value is string;
An http, https or ftp URL with something after the scheme and no whitespace anywhere. A bare host such as "example.com" is not one.
isX and nonX answer a question and never interrupt control flow; requireX and requireNonX hand the value back or throw. The scheme is explained in Validation conventions.
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The value to check. |
Returns
boolean — true when the value is a URL; otherwise false.
In TypeScript the guard narrows value to string inside the branch.
Examples
What passes and what does not
isUrl("https://example.com"); // => true
isUrl("http://example.com/a?b=1"); // => true
isUrl("example.com"); // => false
isUrl("https://"); // => false
isUrl("https://exa mple.com"); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.