You can open a QWeb report as a HTML or PDF in a browser via URL:
http://<server-address>/report/<report-type>/<report-name>/<object-id>
For example, if you want to open pdf report for sales order with ID 40 on your local server the URL should be:
http://localhost:8069/report/pdf/sale.report_saleorder/40
how about for version 11?
It is same in version 11.