The research found that almost half – 49 per cent – of addresses were unable to get 6.7Mbps, the average broadband download speed across the UK.
More than a third (34 per cent) struggle to get speeds higher than 5Mbps and a quarter (23 per cent) are on less than 4Mbps, 1. 68 million speed tests found.
Hereford was found to the slowest broadband city, with average speeds of 3.1Mbps.
The East Sussex village of Winchelsea struggled along with an average speed of just 1.1Mbps.
The government has put super-fast broadband high on its list of priorities and wants the UK to be the fastest broadband nation in Europe by 2015.
But this research suggests we could be way off the mark.
"Britain might be riding the wave of a super-fast broadband revolution, but for 49 per cent who get less than the national average broadband speed, the wave isn't causing so much a splash as a ripple," said Julia Stent, director of telecoms at uSwitch.
Virgin Media already offer broadband speeds of up to 100Mbps and BT has pledged to offer speeds of up to 300Mbps by 2013.