
Samsung Galaxy J2
The latest firmware for Samsung Galaxy J2 (SM-J200GU) is J200GUDXU3AQL1 with Android 5.1.1 (Lollipop), released on December 12, 2017 for 9 regions (CSC). Every official firmware build for SM-J200GU, 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/J200GUDXU3AQL1
All 14 builds in our database run Android 5.1.1 (Lollipop). The newest build, J200GUDXU3AQL1, was released on December 12, 2017. No new build has appeared for 108 months, so regular updates for this model have most likely ended.
Specifications of SM-J200, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-J200BT

SM-J100VPP

SM-J210F

SM-J106M

SM-J105Y
The newest firmware for SM-J200GU runs Android 5.1.1 (Lollipop): build J200GUDXU3AQL1, released on December 12, 2017.
The latest build for SM-J200GU, J200GUDXU3AQL1, was released on December 12, 2017 (8 years ago).
SM-J200GU has had no new firmware for 108 months, so regular updates have most likely ended.
Yes, all firmware files for SM-J200GU are 100% official, original, and obtained directly from Samsung servers.
To flash SM-J200GU, 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-J200GU.