The NYPD will begin testing body cameras on cops as soon as Friday, Mayor de Blasio and Commissioner Bill Bratton announced Wednesday.

A pilot program is kicking off in three different commands as the city waits for a ruling in the death of Eric Garner, who died from a police chokehold last July.

De Blasio said the new technology is one of many reforms the NYPD is undertaking to create greater transparency and accountability from police forces.

“When something happens, to have a video record of it, from the police officers’ perspective, is going to help in many, many ways,” he said. “And God forbid, when something goes wrong, we are going to have a clearer sense of what happened.”

Eventually, 54 cops from six different commands will voluntarily be a part of the three-month pilot program, testing two cameras, one made by Vievu and another from Taser International.

Starting Friday, 27 officers from three commands – Precinct 120, 40 and PSA 2 – will wear Vievu cameras on their shirts.

De Blasio showed off the new devices at the press conference, remarking on how “light” and easy to use they are. They weigh about 3 ounces and are activated by sliding down a lens cover. The camera itself starts filming a 68-degree field of view about 3.8 seconds later.

Bratton also outlined the seven situations that cops are allowed to use their cameras in, which include all reasonable suspicion stops, law enforcement encounters, vehicle stops, arrests, any encounters that escalate and vertical patrols.

Officers will place their cameras in a docking device at the end of their shifts to upload their footage into a system.

Retaining that data is the most expensive aspect of the technology, and since there’s no way to store such an immense volume of data on site, the NYPD will likely use a cloud storage system, De Blasio said.

Each device costs about $100 a month to maintain – or $1,200 for each device every year. The pilot program itself, which is being funded by the Police Foundation, will cost $50,000.

“This is a huge expenditure of funds as well as a time commitment, so we want to make sure we get it right,” Bratton said.

Despite the steep cost, Public Advocate Letitia James said the city will end up saving money on police-related lawsuits.

“It’s cheaper to buy these cameras than it is to pay hundreds of millions of dollars in lawsuits,” she said.

A group of NYPD officers are currently in route to London, where British law enforcement is about to buy 15,000 to 20,000 cameras for a force of equivalent size, Bratton said.

Comparing it to “candid camera,” their devices will be capable of showing the suspect what’s being recorded, which could influence their behavior, Bratton said.

British police have been experimenting with the new technology since 2005, he added.