Grammar and usage aside, DNS will accept “.” at the end of domains. “.” by itself means “root” so, for example, amazon.com and amazon.com. will both return the same DNS records.
To be sure:
Deleuze:~ ryan$ dig amazon.com. amazon.com +short | sort -nr | uniq -c 2 72.21.214.128 2 72.21.211.176 2 72.21.194.1
But since you’re talking about URLs at large, I’d recast the sentence. Clarity should always trump pedantry. And besides, it’s best to end sentences with words that have an impact; URLs are mere textual flotsam… end your sentences with solid stuff.