Australia has slipped further in global broadband speed rankings, underlining the challenges facing the rollout of fast and reliable internet connections under the National Broadband Network.

While speeds improved slightly, Australia dropped three places to 62nd for fixed broadband in the latest Ookla Speedtest Global Index, putting the country far behind many other advanced economies and a handful of developing nations. The Australian download speed of 35.11 Mbps recorded for March is far below the global average of 57.91 Mbps.

Australia's internet speeds are below the global average, according to a new survey. Credit:James Alcock

The Ookla survey ranked Australia's mobile internet speeds at 5th globally, with significantly better performance than average.

Labor has seized on the updated broadband ranking, blaming the Coalition government's "multi-technology mix" rollout of the National Broadband Network. The opposition recently ruled out a rapid, large-scale fibre upgrade of the network, opting for $185 million of targeted improvements and a review of the $50 billion project.