comment/s

"Without comment" is better, but in an informal sense no-one would mind if you said "I posted the link without (adding any) comments"

Thanks, Mc Tag.

When someone asks for my opinion, should I say "No comment" or "No comments"?

Many thanks.

"No comment" is the normal one to choose.

That would be a shorter form, I would suggest, of something like "I have no comment to make"

But the difference is rather a fine one: for example, a questioner might ask "Have you any comments to make?" (maybe hoping for a variety of them), and so I would say the plural form is not incorrect in many cases.