Memviz takes the trace generated by memtracker2json and produces the HTML, JavaScript and data to visualize it.
% git clone https://github.com/znik/memvis.git
% make
MEMVIS_HOME=/path/to/memvis
cat memtracker-json-trace.json | $MEMVIS_HOME/analyzer -p "Trace description" -d $MEMVIS_HOME/server/data
% cd $MEMVIS_HOME/server
% ./run_server.sh
Then open the browser and type in the name of the machine where you launched the above command and port 8080, for instance: "localhost:8080" if running locally.
You can also copy the entire $MEMVIS_HOME/server directory (including the $MEMVIS_HOME/server/data) to a directory of an existing web server and access it via the browser.