Hello,
I use this great trick to have both a pdf and html export of tikz
images:
#+header: :file (by-backend (latex "tp6-tree.tikz") (t "tp6-tree.png"))
#+header: :imagemagick yes :iminoptions -density 600 :imoutoptions -geometry 800
#+header: :results file raw
#+header: :fit yes
#+header: :headers '("\\usepackage{tikz}")
#+begin_src latex
\begin{tikzpicture}
…
\end{tikzpicture}
#+end_src