Reference:

http://tex.stackexchange.com/questions/195608/why-tex4ht-does-not-accept-setcountertocdepth-in-report-class-but-it-does-in

When setting \setcounter{tocdepth}{0} in report class, then the PDF file shows only the chapters as expected in toc, but the HTML shows both chapter and sections in toc.

When setting \setcounter{tocdepth}{1} in artice class, then the PDF file shows only the sections as expected in toc, and now the HTML shows only the sections in toc as expected as well.

So, the question is: Why tex4ht agrees with pdf toc for article and not for report?

When compiling this file

\documentclass{report}%
\setcounter{tocdepth}{0}
\begin{document}
\tableofcontents
\clearpage

\chapter{This is chapter 1}
some text in chapter 1
\section{1}
some text in chapter, section

\chapter{This is chapter 2}
some text in chapter 2
\section{1}
some text in chapter, section

\chapter{This is chapter 3}
some text in chapter 3
\section{1}
some text in chapter, section

\end{document}

The section is added to the TOC in html. This is wrong. Only chapter should show up in TOC.

This was on TexLive 2014