Opposition Leader Tony Abbott won Sunday night's leaders' debate, according to results from the ABC's policy comparison tool.

Forty-one per cent of respondents who watched the debate gave it to Mr Abbott, compared to 35 per cent for Prime Minister Kevin Rudd.

While some social media measures including Twitter and the election 'worm' on one commercial television channel scored the debate for Mr Rudd on Sunday night, Vote Compass respondents gave the edge to Mr Abbott. 

However, 24 per cent of respondents who had watched the debate did not see a clear winner, opting for 'don't know'.

Since its launch on Sunday August 4, Vote Compass has captured more than 675,000 responses.

The data has been weighted to reflect the Australian population using demographic variables from the most recent Census. 

The data on the debate was captured from 7.30pm on Sunday night when respondents were asked whether they watched the televised debate, and if they did: "Who won the debate?"

When broken down by gender, men were more likely to give the debate to Mr Abbott over Mr Rudd.

There were also state by state differences, with Queenslanders awarding the debate to Mr Abbott by a greater margin than other states.

The ACT was the only state or territory which thought Kevin Rudd won the debate, with 41 per cent of Territorians declaring Mr Rudd the winner against 32 per cent for Mr Abbott.

The effective sample size for the question of who won the debate was 10,200 respondents.