The authority that runs Naplan has apologised “unreservedly” for a disruption to a “significant number” of schools on its first day, as some students had the standardised test postponed while others did not.

The chief executive of the Australian Curriculum, Assessment and Reporting Authority (Acara), Stephen Gniel, said the technical issue, identified at 9.20am, stopped some students from logging on to the online platform for their writing assessments.

Schools were told by Acara to “pause” the Naplan testing for over 1 million students nationwide while the glitch was investigated, with one education expert dubbing it a “really unfortunate mess”.

Gniel said the issue was fixed by its technology provider, Education Services Australia, at about 11.15am.

At 11.30am, schools were told they could resume testing – however some schools elected to postpone the testing, while others proceeded.

The shadow education minister, Julian Leeser, said he had written to his counterpart, Jason Clare, asking how he would ensure fairness for students whose test was interrupted compared with those who completed it normally.

“This … creates deep systemic problems,” he said. “This failure could skew the entire dataset.”

Clare said he had rebuked Gniel for the situation and the “bottom line” was that “this is not good enough”.

“It’s a disruption to teachers, students and also parents,” he said. “I’ve made that very clear to the head of Acara.”

Gniel thanked test administration authorities in each state in territory, who work with more than 9,400 schools, for “resuming the testing and ensuring we support students to complete all tests”.

Gniel said he was “unable to say” how many students were affected by the incident but all year 3 students, who still complete their writing tests on paper, went ahead as normal.

He said Western Australian schools hadn’t started testing for the day when the incident occurred due to their different timezone and, as of 11.30am Queensland time, about 100,000 Queensland students in years 5, 7 and 9 had completed their tests.

“Acara is … working with test administration authorities to make sure all schools are provided with support and advice to minimise any impact on students arising from this incident,” he said.

“We have measures in place to ensure students are not disadvantaged as a result of this technical issue. Rest assured, Education Services Australia will conduct a full and thorough technical investigation.”

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Naplan 2026 dubbed a ‘mess’ and a ‘stuff up’

Late on Wednesday morning, schools posted to social media advising parents and carers that the tests would be delayed as a result of the outages. Some tests were unaffected while others were pushed back to Thursday depending on the access they’d had to the digital platform.

Erskine Park high school in western Sydney said on Facebook: “Due to technical issues with the Naplan online server, a number of schools, including ours, were unable to access Naplan today. An updated timeline will be shared.”

Rooty Hill public school in western Sydney said it would postpone Naplan assessments due to the “statewide” issues, while Sydney’s International Grammar School said it had received guidance from Acara that writing tests for years 3 and 5 would “resume tomorrow”.

An associate professor in learning analytics at Adelaide University, Vitomir Kovanovic, said the situation had been a “really unfortunate mess”.

“It’s a very tricky system to test in advance … and there’s no going back if you mess up like this,” he said. “Even if you give [students] another test, it will always look unfair if one student could log in and one couldn’t.”

Victoria’s shadow education minister, Brad Rowsell, said a “legitimate question” must be asked about the reliability of this year’s Naplan dataset given the “stuff up”.

Server error thought to be issue

Before the tests began, parents were sent a 35-page guide to installing a locked-down browser for assessments, which prevents students from using other applications or websites during testing.

The document said the browser would be installed by the school technical support officer. But students with their own devices would need help to set up their device for assessments.

According to reports on social media, an error reading “communication to the server has been lost” was displayed on the screens of students during tests.

About 1.4 million students are expected to complete this year’s Naplan tests, which transitioned to fully online in 2022 after trials away from paper began in 2016.

Year 3 writing tests are still completed on paper.

In 2019 Naplan test computer glitches prompted the Victorian government to allow schools to return to pen-and-paper assessments.

A professor of political education at the University of Sydney, Murray Print, said reverting to paper testing may not ensure a smoother evaluation.

“Naplan is a census assessment, so there are literally tens of thousands of students who are participating in this,” he said.

“If we were to revert to pencil and paper, it would take an inordinate amount of time in order to get the data back and teachers wouldn’t be able to use the information effectively by the time they received it.

“What this does suggest is we need a rigorous system and the organisations involved need to be well and truly resourced to do the job effectively.”