
Samsung Galaxy Tab4 8.0
The latest firmware for Samsung Galaxy Tab4 8.0 (SM-T335L) is T335LKLU1BPL1 with Android 5.1.1 (KitKat), released on December 8, 2016 for 1 region (CSC). Every official firmware build for SM-T335L, 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/T335LKLU1BPL1
SM-T335L started on Android 4 and has received 1 major Android upgrade; it now runs Android 5.1.1 (KitKat). The newest build, T335LKLU1BPL1, was released on December 8, 2016. No new build has appeared for 120 months, so regular updates for this model have most likely ended.
Specifications of SM-T335, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-T290N

SM-T537A

SM-T800X

SM-T807V

SM-T230X

SM-T230NY

SM-T237V

SM-T232
The newest firmware for SM-T335L runs Android 5.1.1 (KitKat): build T335LKLU1BPL1, released on December 8, 2016.
The latest build for SM-T335L, T335LKLU1BPL1, was released on December 8, 2016 (9 years ago).
SM-T335L has had no new firmware for 120 months, so regular updates have most likely ended.
Yes, all firmware files for SM-T335L are 100% official, original, and obtained directly from Samsung servers.
To flash SM-T335L, 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-T335L.