Figures released by market research company Hitwise show that charity websites recorded 0.1046 per cent of the overall share in March. This doubles the 0.052 per cent recorded in March 2004.
Humanitarian charities enjoyed the biggest rise, a massive 336 per cent, mainly because of the Asian tsunami, according to market research company Hitwise.
But the success of other charity websites suggest the voluntary sector's growing online popularity is a result of more than the impact of the disaster.
"Charities have become a lot more internet-savvy," said Hitwise senior research analyst Heather Hopkins. "They are now promoting themselves much better on the web."
Voluntary organisations have become particularly smart at using events to recruit visitors, added Hopkins. "Specific events, such as sponsoring people to take part in marathons, are a great way to drive traffic to a website," she said.
The RSPB's annual Big Garden Birdwatch in early February produced a six-fold increase in the market share of the charity's website. But it continued to draw visitors after the event: it was the fifth most popular site in March.
Comic Relief's website for1 to Red Nose Day, which took place on 11 March, received twice as many visits as any other charity website during the month.
The Hunger Site, which gives food to the poor each time someone visits, was the second most popular site, outperforming better-known sites such as Make Poverty History. "Its success seems to be largely due to successful email campaigns," said Hopkins.
The Disasters Emergency Committee was the most popular charity website in January, but has since returned to relative obscurity.
But other aid organisations such as Oxfam have built on the interest in their sites that the Boxing Day tsunami stimulated.
"Because of the tsunami, people wanted to react immediately and gave online," said Hopkins. "Since then, people have been more likely to return to those websites."