Offline codes are offline health codes. After the health code is generated, it can be downloaded and printed on paper, which can be carried by the elderly and children, and marked with the effective time.
This off-line code also has anti-counterfeiting function, which can scan the off-line code through scanning function, call the interface for real-time verification, and query the health status and expiration of the red, yellow and green codes. In addition, foreigners can also apply for a health code in a small program with valid identity documents such as passports.