When to Include a URL
If the web page might be difficult to find through a search engine, you might want to include a URL in your citation. You should also include a URL if your instructor or editor asks for this information. But don't rely on a URL for your reference -- because websites change, you should always print or save a copy of the page you referenced, according to the Purdue Online Writing Lab.
Works Cited Format
If you decide to include a source's URL, place it at the end of the full citation on the Works Cited page, after the date of access. Use angle brackets to enclose the URL and put a period after the final bracket. For example, your citation for Google would appear as: http://www.google.com. If the URL is long enough to require a line break, break it after a slash.
An in-text citation for a website should include only the first item listed in the Works Cited citation, which may be an author name, an article title, a website name or another item. Do not include URLs in in-text citations. In-text citations for websites shouldn't include page or paragraph numbers either, according to the Purdue Online Writing Lab.