Coop @ home hopes the new system will lead to higher turnover, Sunday newspapers reported.
The test has been launched against the backdrop of falling sales as shoppers take advantage of lower euro prices over the Swiss border.
August Harder, Coop's head of IT, told the Schweiz am Sonntag that new software developed in Germany is being used to analyse individuals' shopping orders.
In recent weeks reductions and special deals have been adjusted in line with these orders, with customers receiving personalized money-off coupons for certain items.
“We are still in the testing phase but hope to play a leading role in this area in Switzerland,” Harder said.
For the time being, personalized pricing is limited to Coop @ home with its range of food and near-food products.
“But if the test is successful it could be expanded to all our online stores as well as our shops,” Harder told the paper.
The test phase is expected to run until early 2016.
Coop's biggest competitor, Migros, has ruled out adopting a similar pricing policy in its online store, LeShop.
“We want to treat all our customers equally and not discriminate against anyone on the basis of price,” spokesman Dominique Locher said, according to the newspaper report.
The Swiss consumer protection foundation criticized Coop over the move.
Spokesperson Sara Stalder told the 20 Minuten newspaper that offering lower prices in return for data was unfair and she warned customers would be indignant at paying different amounts for basic goods.
A number of retailers abroad have employed differentiated pricing. Amazon had to apologise to customers in 2000 when it became clear it was charging customers different amounts for its DVDs.
Even President Barack Obama has weighed in on the issue, warning against personalized pricing in a report issued in February, the newspaper said.