Broadband speeds in the UK are fastest at 4am 04:00, according to a report by comparison site uSwitch.
This is the only time of day when many customers will receive the top speed that was advertised by their internet provider.
Connections are slowest at the start of the working day at 9am and in the early evening.
The report found that internet speeds can fall by as much as 60 per cent during peak times.
Downloads also suffer, with the average speed falling from 14.83 Mbp/s to 10.72 Mbp/s in the busiest periods.
There is considerable regional variation, with the highest speeds in Birmingham and Middlesbrough, where they can be twice as fast as those in areas with the slowest connections such as Swansea and Aberdeen.
uSwitch's Julia Stent said: "This research shows the incredible strain that is placed on broadband when everyone logs on at the same time, particularly in densely populated areas."
She added that customers should run an online speed test at home to ensure they are getting the best service available in their area.
Posted by Craig Roberts