
Samsung Galaxy J7(2017)
The latest firmware for Samsung Galaxy J7(2017) (SM-J730K) is J730KKKS5CUD1 with Android 9 (Pie), released on May 17, 2021 for 1 region (CSC). Every official firmware build for SM-J730K, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/J730KKKS5CUD1
SM-J730K started on Android 7 and has received 2 major Android upgrades; it now runs Android 9 (Pie). The newest build, J730KKKS5CUD1, was released on May 17, 2021. No new build has appeared for 66 months, so regular updates for this model have most likely ended.
Specifications of SM-J730, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-J730GM

SM-J737A

SM-J727A

SM-J720M

SM-J710FN
The newest firmware for SM-J730K runs Android 9 (Pie): build J730KKKS5CUD1, released on May 17, 2021.
The latest build for SM-J730K, J730KKKS5CUD1, was released on May 17, 2021 (5 years ago).
SM-J730K has had no new firmware for 66 months, so regular updates have most likely ended.
Yes, all firmware files for SM-J730K are 100% official, original, and obtained directly from Samsung servers.
To flash SM-J730K, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-J730K.