A blaring emergency warning alert Australians had been warned about was anti-climactic for some – and totally missed by others.

Almost every phone in the country, alongside some smartwatches and tablets, was supposed to let off a loud noise at about 2pm AEST and receive a pop-up notification with the text “TEST MESSAGE” and “NO ACTION IS REQUIRED”.

The event was the first nationwide test of a new warning system called AusAlert, which will be deployed in October to prepare Australians for fires, floods, terrorist incidents or health emergencies.

The federal government has spent the past week telling the public about this test alert.

But for many, it came and went in just a few seconds.

Indigo Miller was working from home in Canberra when her colleagues reminded her of the notification.

“I was counting down for two minutes before,” she says.

“But it was pretty anti-climactic and I think I accidentally clicked it away.

“Mine also wasn’t super loud so if I was outside and my phone was inside, I don’t know if I would hear.”

Miller had attempted to film herself recording to try capture the sound of the alert, but her phone cut out as the siren went off.

Busker Dani Bainbridge was about to start performing at Sydney’s Hyde Park when the alert began pinging.

“It did the job, I think,” she said.

But others did not receive an alert at all.

Guardian Australia received reports of mobile users whose phones got a notification but did not blast a sound.

Prior to the test, the National Emergency Management Agency received advice about 80% of Apple iPhones would ring, as well as 16m Android devices.

It also said the alert would go to iPhone models 11 and up running iOS 26.4 or later, Apple Watch models SE2, SE3, Series 6 and up running watchOS 26.4 or later, and Android devices running Android 12 or later.

Guardian Australia was told of an iPhone 15 Pro, iPhone 17 Pro, iPhone 12, a Samsung phone and other devices not receiving a notification despite being on.

The federal emergency management minister, Kristy McBain, said 94% of targeted cell towers had successfully broadcast the alert.

“Don’t worry if you did not receive an alert – this could be because you were not in a coverage area, your software was not up to date or your device was incompatible,” she said.

“Nema will continue to analyse the technical and performance data and engage with emergency service organisations around the country.”

Asked if it would ever be completely successful, McBain said “there is no one avenue of communication that is 100% successful”.

“This technology is more reliable than the current text-based technology,” she said.

“But as I said, this is just another tool in the toolkit for emergency service agencies, who are doing a really good job in communicating to communities that are at risk during a natural disaster.”

Ahead of the AusAlert test, domestic and family violence advocates raised concerns about the risk of the notification exposing “safe phones” and urged people to keep devices hidden for safety reasons.

AusAlert interim coordinator general Pat Hetherington said the advice for people who have safe phones and hidden phones is for them to be switched off for a 24-hour period.

Businesses and people going about their daily lives reacted to the impending alert in different ways.

Before the alert, those who had bought Imax tickets for Christopher Nolan’s much-anticipated The Odyssey at the 1.50pm session in Sydney were told by workers to switch off their phones.

Though some still went off, they rang out during the ads that played before the film, according to people present in the theatre.

At the State Library of NSW, the siren cut through the typical wall of silence, offering some reprieve to cramming Year 12 students and even waking up one high schooler who was nodding off at his laptop.