Perhaps additional closing HTML tags (for example, </TR>) represent an additional cost for the HTML parser browser?

According to this last question, the HTML 4 standard indicates that end tags </TD>/ </TR>are optional.

The question is, if you write your HTML code that excludes those closing tags, will this affect the amount of work that the HTML browser browser needs to do anyway?

I understand that the difference - even if there is any effect - is likely to be insignificant and does not matter in practice - this question does not have a purely theoretical curiosity.

My own thinking is that there will be a modest gain, from less text for parsing and without loss, because in any case there should be code to parse the initial tag inside TD or TR, even if their closing tags are not necessary; and therefore, the only code value to make them optional is to check whether the open tag contained in is <TD>, with <TD>or <TR>without a previously discovered nested tag <TABLE>... not like a very expensive add-on.