> For the complete documentation index, see [llms.txt](https://docs.internetobject.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.internetobject.org/schema-definition-language/data-types/string/url.md).

# URL

`url` is a `string` shortcut (see [String Types](/schema-definition-language/data-types/string.md)) whose value MUST be a valid URL. It shares the string [MemberDef](/schema-definition-language/advanced-schema-concepts/memberdef.md) and adds URL-format validation.

> **Quote URL values.** A URL contains `:` and `/`, which end an unquoted (open) string, so URLs must be written as quoted strings.

```ruby
website: url
---
~ 'https://example.com'         # ✓
~ "https://example.com/p?q=1"   # ✓
~ 'not a url'                    # ✗ invalid-url
```

Restrict to a fixed set with `choices`:

```ruby
homepage: { url, choices: ['https://a.com', 'https://b.com'] }
---
~ 'https://a.com'    # ✓
```

## See Also

* [String Types](/schema-definition-language/data-types/string.md) · [Email](/schema-definition-language/data-types/string/email.md)
* [MemberDef](/schema-definition-language/advanced-schema-concepts/memberdef.md)


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