Lateral flow tests, which give a result in about 20 to 30 minutes, will be used to determine if people have the virus.
Merthyr Tydfil has become the first place in Wales to begin testing the coronavirus for people with no symptoms.
Everyone who lives or works there can now get a free trial.
A similar process follows in Liverpool, with members of the Armed Forces reunited with local authorities.
The aim is to identify the most common cases and to prevent the spread of the disease.
The Merthyr Tydfil Rhydycar Recreation Center is open for testing on Saturday and other sites will go online later this month.
Lateral flow tests are used – they give the result in about 20 to 30 minutes and do not need to be sent to the lab.
People who test it will also receive a traditional swab test – with a high level of accuracy – and will be asked to return home to isolate themselves.
Health Secretary Matt Hancock has given quick tests to all local authorities in England, as well as to independent states.
Merthyr Tydfil had the worst rate of infection in the UK in early November but the recent closure of the “firebreak” in Wales appears to have had a major impact.
Cases in this area ranged from about 770 people per 100,000 to less than 260.
Blaenau Gwent is now a viral hotspot in Wales, with more than 350 cases per 100,000.
The total number of cases in the country dropped from 10 days to Friday, and there were signs of declining hospital admissions.
The seven-day incidence rate in the country is now 160 cases per 100,000 people, according to First Minister Mark Drakeford.
Despite the success, he said there was “no room” for continued relaxation in Wales.
He added: “If we do all this together, then we can have a way to Christmas and hope to see family and friends at this happy time.”
Mr Drakeford said talks on the UK’s approach to Christmas rules are set for next week.