The Clap For Our Carers event set an all-time record for internet traffic, Virgin Media has said.
More people were uploading videos of applause and other celebrations for NHS workers than at any time in the past, the network said.
The campaign saw people across the country urged to open their doors and windows and make as much noise as possible to celebrate healthworkers who are caring for those with Covid-19.
Around 8pm, as the event began and households across the country put down devices to take part in the celebration, traffic sharply dipped, according to the network. Downstream traffic – where devices are receiving data – sharply fell as people left their houses.
But soon after that upstream traffic surged, presumably as people flocked to share the videos and photographs they had taken of the celebration.
Footage of the events spread quickly around social media as videos showed entire streets take part in the event, and celebrations from across the country.
Upstream traffic – data sent by people when using programmes such as video calls – has increased significantly during daytime hours, as the public stay at home during the coronavirus lockdown.
Virgin Media said upstream traffic on its network is up more than 150 per cent on the previous month, due to a rise in video conferencing and digital classrooms.
Over the past two weeks, data use on the Virgin Media network has risen gradually, with a "new normal" emerging as usage begins to level out, the company added.
Although daytime traffic levels have climbed, they remain below those experienced in the evening peak.
Despite increased demand overall, Virgin Media insists its network has "ample capacity".
Additional reporting by Press Association
