Cetizen

Cetizen is a Korean mobile-device marketplace and information platform operated by Cetizen Co., Ltd. Established in 2000, it helps consumers compare phones, check used-device prices, and buy or sell pre-owned products through a range of services. Its secondhand marketplace covers smartphones, tablets, and wearables, with listings for brands including Samsung and Apple. Buyers can review model information and average market prices, while sellers can register items for sale. Cetizen also offers an escrow-style safe-trading service that holds payment during private transactions, along with transaction guidance and support resources.

Beyond the marketplace, the platform provides comparisons of budget mobile plans and a mobile-bill calculator to help users assess costs and savings. Visitors can explore product specifications, compare phones side by side, and read professional reviews and product news. The site also links to practical tools for checking discount eligibility, lost or stolen devices, and Apple warranty coverage. By bringing together resale listings, pricing information, telecom-plan comparisons, and device reviews, Cetizen supports consumers researching mobile products and services.