regex101: JavaScript Match Workspace

Regular Expression

<p>(\s*)(<a(.*)>)?(\s*)(https?:\/\/)?(w{3}\.)?(youtube\.com|youtu\.be)\/(watch\?v=|embed\/)?([A-Za-z0-9-_]{11})(\S*)(\s*)(<\/a>)?(\s*)<\/p>

New

No protocol:

<p>youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>www.youtube.com/watch?v=dQw4w9WgXcQ</p>

HTTP or HTTPS:

<p>http://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>http://www.youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>

With or without “www”

<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>

Youtu.be short links
<p>youtu.be/LQaehcfXvK0</p>
<p>https://youtu.be/LQaehcfXvK0</p>

Embed Urls:
<p>http://www.youtube.com/embed/dQw4w9WgXcQ</p>

URLs with extra parameters:
<p>https://www.youtube.com/watch?v=LQaehcfXvK0&feature=youtu.be</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=RDdQw4w9WgXcQ&start_radio=1&t=1</p>

This URL won’t actually work on YouTube, but it works here, which is somewhat odd? And yet doesn't seem harmful.
<p>youtu.be/embed/dQw4w9WgXcQ</p>

Paragraph tags on separate lines with arbitrary whitespace:

<p>
    www.youtube.com/embed/u8pCsfT1gDU
</p>

<p>
	https://youtube.com/watch?v=dQw4w9WgXcQ
</p>
<p>
	http://www.youtube.com/embed/dQw4w9WgXcQ
</p>

				<p>
	youtube.com/watch?v=dQw4w9WgXcQ

</p>

Paragraph tags with any other text in them, besides the URL:

<p>This shouldn’t work: https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://youtube.com/watch?v=dQw4w9WgXcQ nor this</p>
<p>
https://youtube.com/watch?v=dQw4w9WgXcQ also not this

</p>


Paragraph tags with links added by markdown-it:

<p><a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ">https://www.youtube.com/watch?v=dQw4w9WgXcQ</a></p>

<p>
	<a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ?something" class="something" id="whatever">
	youtube.com/watch?v=dQw4w9WgXcQ?foo=bar&whatever

	</a>
</p>

Substitution

No protocol:

<p>youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>www.youtube.com/watch?v=dQw4w9WgXcQ</p>

HTTP or HTTPS:

<p>http://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>http://www.youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>

With or without “www”

<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>

Youtu.be short links
<p>youtu.be/LQaehcfXvK0</p>
<p>https://youtu.be/LQaehcfXvK0</p>

Embed Urls:
<p>http://www.youtube.com/embed/dQw4w9WgXcQ</p>

URLs with extra parameters:
<p>https://www.youtube.com/watch?v=LQaehcfXvK0&feature=youtu.be</p>
<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=RDdQw4w9WgXcQ&start_radio=1&t=1</p>

This URL won’t actually work on YouTube, but it works here, which is somewhat odd? And yet doesn't seem harmful.
<p>youtu.be/embed/dQw4w9WgXcQ</p>

Paragraph tags on separate lines with arbitrary whitespace:

<p>
    www.youtube.com/embed/u8pCsfT1gDU
</p>

<p>
	https://youtube.com/watch?v=dQw4w9WgXcQ
</p>
<p>
	http://www.youtube.com/embed/dQw4w9WgXcQ
</p>

				<p>
	youtube.com/watch?v=dQw4w9WgXcQ

</p>

Paragraph tags with any other text in them, besides the URL:

<p>This shouldn’t work: https://youtube.com/watch?v=dQw4w9WgXcQ</p>
<p>https://youtube.com/watch?v=dQw4w9WgXcQ nor this</p>
<p>
https://youtube.com/watch?v=dQw4w9WgXcQ also not this

</p>


Paragraph tags with links added by markdown-it:

<p><a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ">https://www.youtube.com/watch?v=dQw4w9WgXcQ</a></p>

<p>
	<a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ?something" class="something" id="whatever">
	youtube.com/watch?v=dQw4w9WgXcQ?foo=bar&whatever

	</a>
</p>