The research by Nielsen found that in November 2008, 10.3m Britons visited at least one of the ten most popular newspaper websites compared to 8.3m last year, representing growth of 23%
Nielsen said the bumper year for UK newspapers online underscored their growing importance to advertisers.
Despite having the lowest online year-on-year growth of the top UK newspapers, the Guardian remains the most popular online paper, with 3.5m unique UK visitors.
Among the most popular online papers, the Mirror (92%), Independent (85%) and Daily Mail (65%) have had the largest year-on-year growth.
The New York Times is the only non-UK paper in the top ten, with 0.9m British visitors, making it more popular online than UK nationals such as the Financial Times, News of the World and Daily Express.
The Metro was the only regional paper in the list with 0.6m.
Rank/Newspaper site/UK Unique Audience Nov 08/UK Audience Nov 07 Change
1 Guardian -- 3,459/3,044/+14%
2 Telegraph -- 3,142/2,563/+23%
3 Times -- 2,896/2,041/+42%
4 Sun -- 2,711/1,895/+43%
5 Daily Mail -- 2,692/1,631/+65%
6 Independent -- 1,588/859/+85%
7 Mirror -- 1,334/695/+92%
8 New York Times -- 902/824/+9%
9 Financial Times -- 774/587/+32%
10 Metro -- 645/531/+21%
Alex Burmaster, communications director, Nielsen Online, said: "Regardless of what's happening with print circulations, the major papers have had a fantastic year online, all experiencing strong growth in audience numbers.
"It acts as a reminder of how important a part online will play in sustaining the size of audiences the newspapers deliver to advertisers."
The top ten demonstrated a real mix of titles diverging from the print market.
Overall 5.5m Britons visited at least one of the ten most popular magazine websites, in a list easily topped by Autotrader, compared to 4.3m last year with growth of 30%.
The ten most popular magazine websites come from nine different sectors with only technology, represented by PC Advisor and Wired, having more than one showing.
Auto Trader was, by far, the most popular magazine website with 1.8m unique British visitors followed by Which? with 1.1m.
There was good news for the BBC in the magazine list. BBC Good Food came in as the fastest-growing online magazine among the top ten (153% growth) followed by the Radio Times (76% growth).
Rank/Magazine site/UK Unique Audience Nov 08/UK Audience Nov 07/Change
1 Auto Trader -- 1,847/1,784/+4%
2 Which? -- 1,055/822/+28%
3 BBC Good Food -- 745/294/+153%
4 Radio Times -- 566/321/+76%
5 Time Out -- 565/608/-7%
6 Scientific American -- 427/ - / -
7 PC Advisor -- 405/254/+59%
8 NME -- 388/228/+70%
9 National Geographic -- 387/333/+16%
10 Wired -- 370/247/+50%
Burmaster said: "Whereas the highest-circulation print magazines are dominated by retailer publications and TV listings, the most popular magazine sites cover an extremely wide array of sectors from auto sales, consumer reviews, food and TV to listings, science, technology, music and geography.
"Despite this diversity, there is consistency in that almost all the leading magazine sites have had a large increase in audience over the past year.
"As with the newspapers, this provides some great news for publishers in contrast to what's happening with print circulations.
"Furthermore, it shows how key a part online should play in the future strategies of print titles in terms of generating advertising revenue."