The teachers have won the backing of ACT Education Minister Yvette Berry, who is leading a national rethink of the project.

My School, which rates individual schools' performances in literacy and numeracy tests, was updated on Wednesday with last year's examination results.

It now includes a decade of testing outcomes for each school in the country.

The teachers' union has opposed the website since Labor prime minister Julia Gillard made the first results public in 2010.

Australian Education Union ACT secretary Glenn Fowler said on the eve of the latest update that publishing the results of the national tests, known as NAPLAN, was "a spectacular failure that is doing nothing for students".

"It creates an annual circus for a few parents who appear to think there is something profound in this information," Mr Fowler said.

"School-by-school comparisons should not be allowed. Yet that is the pernicious effect of My School.

"It's designed to feed an agenda of choice and competition between schools, which we know has not delivered positive outcomes in schools. Even the OECD says that."

In a rare speech last year, Ms Gillard strongly defended the testing regime, which she called "a huge transparency project".

"Parents in countries like Australia make choices all the time about what school to send their children to," she told an education conference in Dubai.

"Whether they get that information from people who they run into at the shops, out of a tabloid newspaper, or they use the rich and transparent dataset on the My School website, they will make those choices. My own view is that choices about education are better if you have the information."

Yet Ms Berry said on Tuesday the website had been misused.

"I've had concerns about the ways NAPLAN data is reported and used for some time, particularly in the way it facilitates simplistic rankings of schools based on point-in-time testing and puts unfair stress on students, families and teachers," the ACT minister said.

She had received "repeated" complaints about the website from the education community, and said "international evidence suggests that high-stakes standardised testing can work against a high-quality school system".

Ms Berry instigated a review of NAPLAN reporting in November through the national council of education ministers "to assess whether the current approach is working against equitable learning and school improvement".

The ACT is now leading the review.

However, the Australian Curriculum, Assessment and Reporting Authority, which manages NAPLAN testing, said the website did not create league tables from school results.

The authority's chief executive, Robert Randall, said: "We want to promote fair comparisons.

"This is about looking at the school and posing the question: 'If it works at this school, why not that school?'

"There's a whole bunch of data there [on My School]. We want to use that information to encourage literacy and numeracy, and to encourage people to learn from successes in other places."

The association of independent school principals said the website helped parents make informed choices about their children's education.

But its chief executive, Beth Blackwood, added that while it was a "good place for parents to start ... it is important to remember that My School gives only a very limited snapshot of school life".

The website was "no substitute for a personal visit to a school", she said.

The Canberra Times will publish tables this week showing how each ACT school improved its students' literacy and numeracy results over two years.