BEIJING — Online platforms have replaced letters as the main channel for public complaints, according to the National Public Complaints and Proposals Administration (NPCPA).

In the first half of this year, complaints submitted online accounted for more than 50 percent of the total across the country.

Among all online complaints and proposals received by the NPCPA, 80 percent were made on mobile devices, said the administration.

In 2013, an online complaint submission system was put in place, followed by smartphone-based and WeChat channels.

Efforts were also made to build an integrated service platform to enable interconnection and information sharing among agencies, and boost the transparency and efficiency of public complaint handling.